Lucent Technologies 555-661-150 User Manual

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MERLIN LEGEND

Communications System Release 6.1

Network Reference

555-661-150 Comcode 108289703 Issue 1 August 1998

Notice

Every effort was made to ensur e th at the info rm ation in this book was complete and accurate at the time of printing. Ho w ev er, information is

subject to change. See App end ix A, “Customer Support Information,” for im portant information.

Your Responsibility for Your System’s Security

Toll fraud is the unauthorized use of your telecommunications system by an unauthorized party, for example, persons other than your company’s employees, agents, subcontractors, or persons working on your company’s behalf. Note that there may be a risk of toll fraud associated with your telecommunications system, and if toll fraud occurs, it can result in subs tantial additional charges for you r tele com m unications services. You and your System Manager are responsible for the security of your system, such as programming and configuring your equipment to prevent unauthorized use. The System Manager is also responsible for reading all installation, instruction, and system programming documents provided with this product in order to fully understand the features th at ca n int roduce risk of toll fraud and the step s tha t ca n be ta k en to reduce that risk. Lucent Technologies does not warrant that this product is immune from or will prevent unauthorized use of common-carrier telecommunication services or facilities accessed through or connected to it. Lucent Technologies will not be responsible for any charges that result from such unauthorized use. For important inform ation regarding your system and toll fraud, see Appendix A, “Customer Support Information.”

Federal Communications Commission Statement

This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide rea s onable protection agai nst ha rmful interference whe n the equipment is operated in a commercial environme nt. This equipment generates, use s, a nd ca n radiate radio frequenc y ene rgy and, if not installed and used in accordance with the inst ruction manual, may cause harmful interference t o radio communications. Opera ti on of this equipment in a residential are a is likely to cause harmful interference, in which case the user will be req u ir ed to correct the interference at his own expense. For further FCC information, see Appe ndi x A, “Customer Support Information.”

Canadian Department of Communications (DOC) Interference Information

This digital apparatus does no t ex ce ed the Class A limits for radio noise emissions set out i n the radio interference regulati ons of t he Canadian Department of Communications. Le Présent Appareil Numériqu e n’émet pas de bruits radioélectri que s dép assa nt les limites a ppl ic ables aux appareils numériques de la classe A préscrites dans le règlement sur le brouillage radioélectrique édicté par le ministère des C om m unications du Canada.

Trademarks

DEFINITY, HackerTracker, MLX-5, MLX-5D, MLX-10, MLX-10D, MLX-10DP, MLX-16DP, MLX-20L, MLX-28D, and PassageWay, are registered trademarks and Lucent Technologies is a trademark of Lucent Technologies in the US and other countries. NetPROTECT is a service mark of Lucent Tech nol ogies in the US and other countries.

Novell and NetWare are registered trademarks of Novell, Inc .

Ordering Information

Call: BCS Publications Center

Write: BCS Publications Center

Order: Document No. Lucent T ec hnologies 555-661-150

For more information abou t L ucent Technologies documents, refer to the section entitled, “Related Do c uments”.

Support Telephone Number

In the continental US, Lucent Technologies provides a toll-free customer helpl in e 24 hours a day. Call the Lucent Technologies Helpline at 1 800 628-2888 or your Luce nt Te chnologies authorized dealer if you need assistance when install in g, programming, or using your system. Consultation charges may apply. Outside the conti nental US, contact your loc al Lucent Technologies authorized representa ti ve .

Lucent Technolo gies Fraud Intervention

If you suspect you are being victimized by toll fraud and you need technical support or assistance, call Lucent Technologies National Customer Care Center at 1 800 628-2888.

Warranty

Lucent Technologie s provides a limited warrant y on t his product. Refer to “Limited Warranty and Limitat ion of Liability” in Appendix A, “Customer Support Information. ”

Voice 1 800 457-1235 International Voice 317- 322-6791 Fax 1 800 457-1764 International Fax 317-322-6699

2855 North Franklin Road Indianapolis, IN 46219- 1385

Comcode: 108289703 Issue 1, August 1998

MERLIN LEGEND Communications System Release 6.1 Network Reference

Contents

555-661-150

Contents

New Features and Enhancements xv

■ Release 6.1 Enhancements

(August 1998) xv

Prior Releases: Features and Enhancements xix

■ Release 6.0 Enhancements

(February, 1998) xix

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IMPORTANT SAFETY INSTRUCTIONS xxv

About This Book xxvii

■ Intended Audience xxvii

■ How to Use This Book xxviii

■ Terms and Conventions Used xxviii

■ Security xxx

■ Related Documents xxx

■ How to Comment on This Book xxxii

1 Introduction 1–1

■ Networking Concepts 1–2

■ Tandem Trunking and Tandem Switching 1–6

■ Uniform Dial Plan 1–19

■ Centralized Voice Messaging System 1–21

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Contents

2 Call-Handling Scenarios 2–1

■ Networking Guidelines 2–2

■ Network Configuration Scenarios 2–14

3 Feature Interactions 3–1

■ Account Code Entry 3–1

■ Alarm 3–1

■ Allowed/Disallow ed Lists 3–2

■ Authorization Code 3–2

■ Auto Answer All 3–2

■ Auto Answer Intercom 3–2

■ Auto Dial 3–2

■ Automatic Route Selection (ARS) 3–3

■ Barge-In 3–4

■ Callback 3–4

■ Caller ID 3–5

■ Calling Restrictions 3–5

■ Camp-On 3–6

■ Centralized Voice Messaging

(Release 6.1 and Later Systems) 3–6

■ Computer Telephony Integration

(CTI) Link 3–7

■ Conference 3–8

■ Coverage 3–9

■ Digital Data Calls 3–9

■ Direct-Line Console (DLC) 3–10

■ Direct Station Selector (DSS) 3–10

■ Direct Voice Mail 3–10

■ Directories 3–10

■ Display 3–11

■ Do Not Disturb 3–12

■ Extended Station Status 3–12

■ Forward and Follow Me 3–13

■ Group Calling 3–13

■ Hands Free Answer on Intercom (HFAI) 3–15

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Contents

■ HotLine 3–16

■ Labeling 3–16

■ Messaging 3–16

■ Music On Hold 3–17

■ Night Service 3–17

■ Paging 3–17

■ Park 3–18

■ Personal Lines 3–18

■ Pickup 3–18

■ Pools 3–18

■ Primary Rate Interface (PRI) and T1 3–19

■ Queued Call Console (QCC) 3–20

■ Reminder Service 3–20

■ Remote Access 3–21

■ Service Observing 3–22

■ Signal/Notify 3–22

■ Station Message Detail Recording (S MDR) 3–23

■ Speed Dial 3–25

■ System Renumbering 3–26

■ Transfer 3–26

■ Voice Announce to Busy 3–27

■ Voice Messaging Interfa ce (VMI) 3–27

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4 Security 4–1

■ Overview 4–2

■ Facility Restriction Levels and Remote Access 4–5

5 Network Management 5–1

■ General Programming in Private Networks 5–2

■ Non-Local Dial Plan Numbering 5–15

■ Switch Identifiers 5–19

■ Tandem PRI Facilities 5–22

■ Uniform Dial Plan Routing 5–25

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Contents

■ Display Preferences for Intersystem Calls 5–31

6Troubleshooting 6–1

■ Troubleshooting Guidelines and Preparation 6–2

■ Verifying Switch Identifiers 6–4

■ Call to a Non-Local Extension: Unexpected Busy Tone 6–5

■ Call to Non-Local Extension:

Silence or Fast Busy Tone 6–6

■ Call to Non-Local Extension: Warble Tone (Error Tone) 6–11

■ Calls to Non-Local Extensions:

Unexpected Busy Tone 6–13

■ Call to Non-Local Extension Reaches Wrong Extension 6–14

■ Call to Non-Local Extension: Message from CO 6–15

■ Transfer to Non-Local Extension Not Completed 6–15

■ Transfer Call to Non-Local Extension Does Not Return 6–16

■ Conference: Cannot Add Call 6–17

■ DID Calls Not Completed 6–17

■ ARS Calls Are Blocked 6–19

■ Callback Does Not Work 6–20

■ Network Call Transmission Level

(Volume) Too Low or Too High 6–20

■ MLX Displays: Network Call Display Problems 6–22

■ PassageWay Call Display Problems 6–23

■ ARS Calls Go to System

Operator (Unassigned Extension) 6–24

■ DID or PRI Dial-Plan Routed Calls Not Completed 6–24

■ Excessive Line Noise on Voice and Data Calls 6–25

■ Station Message Detail Recordi ng

(SMDR) Reports Do Not Include Calls across the Network 6–25

■ Operator Hears Tones 6–26

■ Calls From a Remote System Do Not

Reach the Centralized Voice Messaging System 6–26

■ Calls From a Remote System to

Centralized Voice Messaging System Get the Wrong Message or Go To Operator 6–29

■ No Message Waiting Light Update 6–30

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Contents

A Customer Support Information A–1

■ Support Telephone Number A–1

■ Federal Communications Commission

(FCC) Electromagnetic Interference Information A–1

■ Canadian Department of Communications (DOC)

Interference Information A–2

■ FCC Notification and Repair Information A–2

■ Installation and Operational Procedures A–4

■ DOC Notification and Repair Information A–5

■ Renseignements sur la notification du

ministère des Communications du Canada et la réparation A–6

■ Security of Your System: Preventing Toll Fraud A–9

■ Toll Fraud Prevention A–10

■ Other Security Hints A–16

■ Limited Warranty and Limitation of Liability A–20

■ Remote Administration and Maintenance A–21

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B Sample Reports B–1

■ Dial Plan Report B –6

■ Non-Local Dial Plan Report B–9

■ Tie Trunk Information Report B–10

■ DID Trunk Information Report B–11

■ General Trunk Information Report B–12

■ DS1 Information Report B–13

■ PRI Information Report B–14

■ Remote Access (DISA) Information Report B–18

■ Disallowed Lists Report B–19

■ Access to Disallowed Lists Report B–19

■ Automatic Route Selection Report B–20

■ Extension Directory Report B–21

■ Extension Information Report B–22

■ Direct Group Calling Information

Report (Local Members Only) B–24

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■ Direct Group Calling Information

Report (Single Non-Local Member) B–25

■ Error Log Report B–26

■ Switch 56 Data Information Report B–27

C Voice/Fax Messaging Systems C–1

■ Supported System Considerations C–2

■ Fax Messaging in a Centralized Voice

Mail Configuration C–4

D Touch-Tone Receiver Requirements D–1

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■ System Requirements for Touch-Tone Receivers D–1

GL Glossary GL–1

IN Index IN–1

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Figures 0

1 Introduction 1–1

1–1 Series Configuration 1–7 1–2 Star Configuration: Five Systems 1–8 1–3 Star Configuration: Three Systems 1–9 1–4 Series Configuration: Four Systems 1–13 1–5 Star Configuration: Three Systems 1–14 1–6 Star Configuration: Five Systems 1–16 1–7 Software Defined Network (SDN) Configuration 1–17 1–8 Uniform Dial Plans 1–20 1–9 Centralized Voice Mail with one VMS/AA for Entire

Network 1–24

1–10 Networked Voice Mail Systems 1–26

2 Call-Handling Scenarios 2–1

2–1 Scenario 1: Overview 2–17 2–2 Scenario 2: Company Floor Plans 2–33 2–3 Scenario 2: Overview 2–45 2–4 Scenario 3: Overview 2–58 2–5 Scenario 4: Overview 2–75 2–6 Scenario 5: Overview 2–89

3 Feature Interactions 3–1

3–1 UDP Calls Recorded at All Systems 3–24 3–2 No UDP Calls Recorded at All Systems 3–25

4 Security 4–1

4–1 Facility Restriction Levels Applied to Network Calls 4–10

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Tables

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Ta bl e s 0

1 Introduction 1-1

1–1 Tandem PRI Trunks versus Tandem Tie Trunks 1-11

2 Call-Handling Scenarios 2-1

2–1 UDP Extension Ranges: Scenario 1 2-22 2–2 Scenario 1: Facilities Planning, Calls Originating

within the private network and Going to the PSTN 2-24

2–3 Scenario 1: ARS Routing Summary, Calls

Originating within the private network and Going to

the PSTN 2-25 2–4 Outside Calls: Scenario 1 2-27 2–5 Intersystem Calling: Scenario 1 2-30 2–6 Work Group Needs 2-36 2–7 Individual Needs 2-38 2–8 UDP Extension Ranges: Scenario 2 2-48 2–9 Scenario 2: Facilities Planning, Calls Originating

within the private network and Going to the PSTN 2-49 2–10 Scenario 2: ARS Routing Summary, Calls

Originating within the private network and Going

to the PSTN 2-50 2–11 Outside Calls: Scenario 2 2-52 2–12 Intersystem Calling: Scenario 2 2-55 2–13 UDP Extension Ranges: Scenario 3 2-61 2–14 Scenario 3: Facilities Planning, Calls Originating

within the private network and Going to the PSTN 2-63 2–15 Scenario 3 ARS Routing Summary: Calls

Originating within the Network and Going to the

PSTN: Systems J & K 2-65 2–16 Scenario 3 ARS Routing Summary: Calls

Originating within the Network and Going to the

PSTN: Systems L & M 2-66 2–17 Outside Calls: Scenario 3 2-68 2–18 Intersystem Calling: Scenario 3 2-71 2–19 UDP Extension Ranges: Scenario 4 2-79

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2–20 Scenario 4: Facilities Planning, Calls Originating

2–21 Scenario 4: Facilities Planning, Calls Originating

2–22 Outside Calls: Scenario 4 2-86 2–23 UDP Extension Ranges: Scenario 5 2-92 2–24 Scenario 5: Facilities Planning, Calls Originating

2–25 Outside Calls: Scenario 5 2-95 2–26 Intersystem Calling: Scenario 5 2-97

within the Network and Going to the PSTN,

Systems E and H 2-82

within the Network and Going to the PSTN,

Systems F and G 2-84

within the Private Network and Going to the PSTN 2-93

3 Feature Interactions 3-1

3–1 Cross-Network Display Inform ation 3-15

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4 Security 4-1

4–1 Calling Restrictions and Security Feature Planning

in Networks 4-3 4–2 Recommended Settings for Tie and Non-Tie Default

COR and Callback 4-9 4–3 Facility Restriction Levels 4-11

5 Network Management 5-1

5–1 Cross-Network Display Inform ation 5-11

B Sample Reports B-1

B–1 Sample Report Pages B-1 B–2 System Reports B-2

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D Touch-Tone Receiver Requirements D-1

D–1 TTRs Required by VMS/AA D-2 D–2 System Requirement for TTRs D-3 D–3 TTRs Required for Primary Delay Announcement

Devices When Using Prompt-Based Overflow D-3 D–4 TTRs Required for Secondary Delay Announcement

Devices When Using Prompt-Based Overflow D-4 D–5 Modules with TTRs D-4

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New Features and Enhancements

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New Features and Enhancements

Release 6.1 Enhancements (August 1998) 0

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Release 6.1 includes all Release 6.0 functionality, plus the enhancements listed below.

Private Networking 0

Release 6.1 enhances the functioning of the networked MERLIN LEGEND Communications System in a number of ways:

■ Centralized Voice Messaging

■ Group Calling Enhancements

■ Transfer Redirect

■ Direct Station Selector

■ Call Forwarding

■ SMDR

■ Decrease in Call Set-Up Time

■ PRI Switch Type Test

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Centralized Voice Messaging 0

One or more MERLIN LEGEND systems (Release 6.1 or later) can share the voice messaging system (VMS) of another MERLIN LEGEND system, provided the systems are directly connected to the system with the VMS. In this configuration, the system containing the VMS is known as the hub. This sharing of

the VMS is called “Centralized Voice Messaging.” Centralized Voice Messaging includes the functions of voice mail, Automated Attendant, and fax messaging. See the

Network Reference

Messaging. Centralized Voice Messaging offers the following benefits:

■ Private-networked MERLIN LEGEND systems do not need a local VMS.

Having systems use a centralized VMS instead of separate VMS’s is more economical.

■ Users that travel between sites can dial the same digits anywhere in the

private network to access the voice messaging system. For example, a salesperson headquartered in Cincinnati can dial the same four digits at the company’s Los Angeles office to retrieve voice messages.

for detailed information about Centralized Voice

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■ Productivity is enhanced because messages can be forwarded and

broadcasted to all personnel within the private network.

■ Calling groups on networked systems can send overflow coverage to a

shared VMS, so that an incoming caller can leave a message instead of waiting in a queue.

■ The VMS can light the Message Waiting lights on multiple MERLIN

LEGEND systems in a private network. This greater efficiency saves time because a user only has to look at his or her telephone to determine if he or she has a message.

Group Calling Enhancements 0

A calling group can have a Dial Plan and exists on another MERLIN LEGEND Communications System connected by a tandem trunk to the local system. If a calling group contains a non-local member, the non-local member must be the group. See the

Network Reference

A calling group containing a single non-local member can be used for the same purposes as a calling group containing local extensions, including:

■ Night Service. Night Service coverage can be provided across a private

network to a centralized Automated Attendant, a non-local calling group, a QCC queue, a DLC, or any individual extension on the remote system, such as a night bell.

single

non-local member that is defined by the Uniform

for details.

only

member in the calling

■ Group Coverage. Group Coverage can be provided across a private

network to a VMS, a non-local calling group, a QCC queue, a DLC, or any individual extension on the remote system.

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■ Calling group overflow coverage. Calling group overflow coverage can

be provided by a centralized VMS, a non-local calling group, a QCC queue, a DLC, or any individual extension on the remote system.

■ Calls directed to another system. Lines connected to remote systems

can be answered by any extension programmed to answer the call, such as a centralized Automated Attendant or a system operator (QCC or DLC).

Transfer Redirect 0

When an Automated Attendant transfers a call to a non-local extension, the transferring MERLIN LEGEND system monitors the call to ensure that it is answered. If the non-local extension is not available or the call is not answered within the transfer redirect timeout period (fixed at 32 seconds), the call stops ringing at the non-local destination and is redirected to the extension on the same system as the Automated Attendant that is programmed to receive redirected calls. This redirect extension can be a QCC queue, a calling group, or an individual extension.

Direct Station Selector 0

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Now users can press a Direct Station Selector (DSS) button for a non-local extension to make or transfer calls to that extension. However, no busy indication is displayed by the DSS for non-local extensions.

Call Forwarding 0

The Forward feature now can be used to send calls to non-local extensions across the private network.

SMDR 0

In addition to SMDR options for non-network calls placed to and from the local system, system managers now can program SMDR to log incoming and outgoing UDP calls, or they can choose to log no UDP calls. The factory setting is to record all UDP calls.

Customers who use a call accounting system may not want to fill the database with calls coming and going across the private network. These customers may choose not to log UDP calls.

Decrease in Call Set-Up Time 0

The set-up time for a call across a private network has been reduced by programming the number of UDP digits expected.

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PRI Switch Type Test 0

A new maintenance test, the PRI Switch Type Test, has been created to allow Lucent T echnologies technicians or authorized dealers to automatically determine if each end of the PRI tandem trunks has been programmed correctly.

Service Observing 0

Service Observing allows one extension to listen in on (observe) a call at another extension. A typical application of this feature is that of a Customer Service supervisor observing how a Customer Service representative handles calls.

The Service Observing group can consist of from one extension to all extensions in the system, including other Service Observers. Up to 16 Service Observing groups can be programmed. The Service Observer and the observed extension must be on the same system.

The observer activates Service Observing either by pressing a Service Observing button and then dialing an extension number or by pressing a DSS or Auto Intercom button. The Service Observer must use an MLX telephone to observe an extension; the telephone at the observed extension can be of any type.

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A warning tone that alerts the observer, the observed extension, and the caller that Service Observing is occurring can be set to On or Off through System Programming. The factory setting is On.

Win SPM 0

The System Programming and Maintenance (SPM) software is now available in a Windows format called

Win SPM

. For Release 6.1 and later systems, Win SPM provides a graphical user interface (GUI) for those tasks must commonly performed by the system manager. Pictorial representations of system components, such as modules and their vintages and the creation of MLX telephone button labels, appear on Win SPM. Win SPM also provides a DOSemulator mode to program tasks not currently supported by the GUI and to program a MERLIN LEGEND system of Release 6.0 or earlier. Win SPM is available on CD-ROM and is supported in Windows 95 Windows 98.

Windows NT Driver 0

Now available is the MERLIN LEGEND Windows NT PBX driver. When coupled with the CentreVU Telephony Services application, the driver provides true serverbased Computer Telephony Integration (CTI). The new driver requires a MERLIN LEGEND system of Release 5.0 or later and servers and PCs that support the applications.

, Windows NT, and

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Prior Releases: Features and Enhancements

Release 6.0 Enhancements (February, 1998) 0

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Release 6.0 includes all Release 5.0 functionality, plus the enhancements listed below.

Private Networks 0

In Hybrid/PBX mode systems only, MERLIN LEGEND Communications Systems can be networked with one another or with DEFINITY Communications Server (ECS) and ProLogix private networks. In previous releases, this functionality is available using tie lines, but users handle calls between networked switches as outside calls. In this release, dialing the pool access code is not necessary for a call going from one networked switch to another. Also, delay-start tie trunks or T1 trunks administered as PRI can act as

Available for Hybrid/PBX mode systems, the private network features of the MERLIN LEGEND Communications System Release 6.0 provide the following advantages for geographically dispersed organizational sites:

■ Intersystem Calling. In a private network, users on one local system can

call extensions on other systems in the network. Release 6.0 can support 2-, 3-, 4-, or 5-digit dial plans. They dial these extensions as inside calls. To implement this function, the system manager programs the extension ranges of remote networked switches to create a non-local dial plan. This programming does not actually affect numbering on the remote system. To correctly set up systems for transparent calling among non-local dial plan extensions, the system manager assigns networking tie and/or PRI tandem trunks to pools. Then he or she programs as many as 20 patterns,

tandem trunks

to connect networked systems.

™

Enterprise

Communications Systems in

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associates with routes, Facility Restriction Levels (FRLs), digit absorption, and digit prepending. This allows ARS-like routing of non-local dial plan calls. In addition, system managers can control whether calling name, calling number, or both are shown at MLX display telephone for incoming calls across PRI tandem trunks.

■ Toll Savings. Private networke d tr unks may allow you to r ealiz e signif ica nt

cost savings on long-distance and toll calls by performing tandem switching in the following two ways:

— Callers on a local system, or individuals dialing in to remote access

at a local system, can reach the public switched telephone network (PSTN) via outside trunks connected to other systems in a private network, avoiding toll charges or decreasing the cost of toll calls. No special dialing is required. For example, an organization might have a main office in Boston and a subsidiary office in New Jersey, connected by networked private tandem trunks between two systems. A user in the New Jersey office who wishes to make an outside call to the 617 area code (Boston) can do so through a line/trunk connected to the system in Boston. For example, he or she might dial,

916175551211. The local ARS tables would route this

call over the private network trunks and use the ARS tables of the remote system in Boston to route this call. The system managers at each end of a private network set up ARS and Remote Access features to implement this functionality.

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— In addition, local organizations or incoming DID calls use private

networked trunks to make intersystem calls between networked systems, which may be geographically distant from one another, also resulting in toll savings.

■ Service Cost Savings. In addition to toll call saving, there are two ways

that organizations can save on service costs incurred from telecommunications providers that provide public switched telephone network access:

— You order a point to point T1 facility from a service provider, then

use system programming to set it up for PRI signalling. As necessary, a service provider can provide amplification on the T1 facility, but does not supply switching services.

— You can tailor your use of PRI B-channels with drop-and-insert

equipment that allows fractional use of B-channels for dedicated data/video communications between systems at speeds greater than 64kbps per channel or 128 kbps for 2B data, while keeping the remaining B-channels for PRI voice traffic. The PRI D-channel must remain active.

— You can tailor use of T1 channels to support both T1-emulated

tandem tie service and T1 Switched 56 service for data communications at 56 kbps per channel, allowing 2B data transfers at 112 kbps. You can also use drop-and-insert equipment to provide fractional T1 use.

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■ Voice Mail and Auto Attendant. Networked systems should have their

own local voice mail and/or auto attendant applications as well as their own external alerts and Music On Hold sources. However, a single auto attendant can transfer calls throughout the network. It can answer only those calls that arrive on the PSTN facilities of the system where it is connected.

Although many features are available using tie trunks for network connectivity, PRI tandem trunks provide greatly enhanced features and faster call setup. For this reason, PRI is recommended over tie functionality in private networks.

Group Calling Enhancements 0

Release 6.0 and later systems include Group Calling features that enhance group calling operations.

Queue Control 0

The system manager can control the maximum number of calls allowed in the primary calling group queue for calls that arrive on certain facilities often assigned to calling groups. When the number of the calls in queue reaches the programmed maximum, subsequent callers receive a busy signal.

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Queue control applies to calls received on the following types of facilities:

■ DID (Direct Inward Dialing)

■ PRI facilities programmed for dial-plan routing

■ All calls transferred from a VMI (voice messaging interface) port

■ Dial-in Tie

Queue control also applies to internal calls to a calling group and calls to a calling group through the QCC.

Internal calls that dial #0 or

and are directed to a calling group administered

#800

as Position-Busy Backup are eligible for queue control. Calls that come in on a trunk assigned to the Queued Call Console (QCC) are not eligible for queue control if the call is directed to a calling group designated as Position-Busy Backup.

Remote-access calls to a calling group, coverage calls directed to a calling group, calls directed to calling group through QCC Position-Busy backup, and all other outside calls are not eligible for queue control.

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Prompt-Based Overflow 0

System managers can activate the Prompt-Based Overflow option. This option allows callers waiting in queue and listening to a delay announcement to press the # key in order to reach the overflow receiver for the group, which may be the QCC queue or another calling group (including a calling group assigned for a voice mail system).

All three overflow distribution options—based on the number of calls, the time a caller has waited, and according to the caller’s prompt—may be used at one time. In this case, time-based and number-of-calls based options take precedence over overflow distribution based on the caller’s prompt.

When prompt-based overflow distribution is used, an extra TTR must be provided for each delay announcement device assigned to the associated calling group. The delay announcement informs the caller of the # key option to exit the queue and leave rather than waiting for an agent. If no TTR is available when a calling group call arrives, the call is not sent to a delay announcement extension.

Centrex Transfer via Remote Call Forwarding 0

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Centrex Transfer via Remote Call Forwarding can be used in all system modes of operation to send outside calls to a remote telephone number or another Centrex station. In this context, the term

outside calls

refers to calls from outside the communications system, which may originate at extensions in the Centrex system but not connected to the local MERLIN LEGEND Communications System.

An outside call that uses this feature is defined as a call that arrives on an analog Centrex loop-start line at the MERLIN LEGEND Communications System. It may arrive directly or be transferred without consultation or without transfer supervision (in the case of an automated attendant). The forwarding call to the outside number is made on the same line/trunk on which the call arrived, conserving system facilities. The following considerations and rules apply:

■ Only outside Centrex calls are forwarded using this feature.

■ The system must be equipped with analog loop-start Centrex lines and a

loop-start lines in the system must be Centrex facilities. Loop-start lines do not have to provide reliable disconnect for use by the Centrex Transfer via Remote Call Forwarding feature.

■ To transfer calls outside the Centrex system, the organization must

subscribe to a Centrex trunk-to-trunk transfer feature.

Activating Centrex Transfer via Remote Call Forwarding is just like activating regular Remote Call Forwarding and requires that Remote Call Forwarding be enabled for the extension. However, the user dials and a Pause character may be required after the

* instead of a dial-out code,

*. The Centrex service provider

determines whether the Pause is needed.

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Prior Releases: Features and Enhancements

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Pause cannot be originated from a single-line telephone or a remote access user. A multiline telephone user in the local system must enter an authorization code to activate the feature.

A remote access user may activate the feature without using an authorization code. Barrier code requirements do apply, however.

Authorization Codes and Remote Call Forwarding 0

In Release 6.0 and later Key or Hybrid/PBX mode systems, forwarding features, including Centrex Transfer via Remote Call Forwarding, but excluding Follow Me, can be activated or deactivated at a multiline telephone by entering the authorization code for the extension from which calls are to be forwarded. The user enters the authorization code, then activates or deactivates the forwarding feature in the normal fashion. This is especially useful for a single-line telephone user who must include a Pause character in a Centrex Transfer via Remote Call Forwarding dialing sequence, because the character cannot be dialed at a singleline telephone. It is also useful when activating Call Forwarding or Remote Call Forwarding at phantom stations, or via remote access (e.g. from another switch in the network). No other features can be used by entering an authorization code in this fashion.

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MERLIN LEGEND Communications System Release 6.1 Network Reference

IMPORTANT SAFETY INSTRUCTIONS

555-661-150

IMPORTANT SAFETY INSTRUCTIONS

The exclamation point in an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the product.

When installing telephone equipment, always follow basic safety precautions to reduce the risk of fire, electrical shock, and injury to persons, including:

■ Read and understand all instructions.

■ Follow all warnings and instructions marked on or packed with the product.

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■ Never install telephone wiring during a lightning storm.

■ Never install a telephone jack in a wet location unless the jack is

specifically designed for wet locations.

■ Never touch uninsulated telephone wires or terminals unless the telephone

wiring has been disconnected at the network interface.

■ Use caution when installing or modifying telephone lines.

■ Use only Lucent Technologies-manufactured MERLIN LEGEND

Communications System circuit modules, carrier assemblies, and power units in the MERLIN LEGEND Communications System control unit.

■ Use only Lucent Technologies-recommended/approved MERLIN LEGEND

Communications System accessories.

■ If equipment connected to the analog extension modules (008, 408, 408

GS/LS) or to the MLX telephone modules (008 MLX, 408 GS/LS-MLX) is to be used for in-range out-of-building (IROB) applications, IROB protectors are required.

■ Do not install this product near water, for example, in a wet basement

location.

■ Do no t ov erlo ad wal l out let s, as this can re sult in the risk of fir e or el ect ric al

shock.

■ The MERLIN LEGEND Communications System is equipped with a 3-wire

grounding-type plug with a third (grounding) pin. This plug will fit only into a grounding-type power outlet. This is a safety feature. If you are unable to insert the plug into the outlet, contact an electrician to replace the obsolete outlet. Do not defeat the safety purpose of the grounding plug.

MERLIN LEGEND Communications System Release 6.1 Network Reference

IMPORTANT SAFETY INSTRUCTIONS

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■ The MERLIN LEGEND Communications System requires a supplementary

ground

■ Do not attach the power supply cord to building surfaces. Do not allow

anything to rest on the power cord. Do not locate this product where the cord will be abused by persons walking on it.

■ Slots and openings in the module housings are provided for ventilation. To

protect this equipment from overheating, do not block these openings.

■ Never push objects of any kind into this product through module openings

or expansion slots, as they may touch dangerous voltage points or short out parts, which could result in a risk of fire or elec trical shock. Never spill liquid of any kind on this product.

■ Unplug the product from the wall outlet before cleaning. Use a damp cloth

for cleaning. Do not use cleaners or aerosol cleaners.

■ Auxiliary equipment includes answering machines, alerts, modems, and

fax machines. To connect one of these devices, you must first have a MultiFunction Module (MFM).

■ Do not operate telephones if chemical gas leakage is suspected in the

area. Use telephones located in some other safe area to report the trouble.

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WARNING:

■

For your personal safety, DO NOT install an MFM yourself.

■

ONLY an authorized technician or dealer representative shall install, set options, or repair an MFM.

■

To eliminate the risk of personal injury due to electrical shock, DO NOT attempt to install or remove an MFM from your MLX telephone. Opening or removing the module cover of your telephone may expose you to dangerous voltages.

SAVE THESE INSTRUCTIONS

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About This Book

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About This Book

The MERLIN LEGEND Communications System is an advanced digital switching system that integrates voice and data communications features. This guide provides information about the networking capabilities of MERLIN LEGEND Communications System Release 6.1 (Hybrid/PBX mode), including tandem trunking, tandem switching, and related private network features.

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Page xxviiIntended Audience

Intended Audience 0

This book is specifically designed to help you fulfill your role as system manager of the MERLIN LEGEND help system managers understand the concepts behind these private networks so that you can plan and maintain networked systems. If you have little or no knowledge of the system, you should consult other system documents before attempting to work with private networks. See “Related Documents” on page xxx

for a list of these guides. This guide is also helpful to MERLIN LEGEND Communications System

distributors and to Lucent Technologies employees working with networked systems.

Communications System Release 6.1. It is designed to

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About This Book

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How to Use This Book 0

This guide includes five chapters:

■ Chapter 1, Introduction. This chapter provides a grounding in the basic

terminology and concepts that you must understand in order to manage a networked system.

■ Chapter 2, Call-Handling Scenarios. Studies several sample network

configurations, demonstrating how the systems are set up for networking, how calls are made and received, and the advantages and disadvantages of each configuration.

■ Chapter 3, Feature Interactions. Describes the ways that system features

work in networks.

■ Ch apter 4, S e curity. Discusses security issues and considerations.

■ Chapter 5, Network Management. Summarizes programming procedures

for setting up and modifying network operations.

■ Chapter 6, Troubleshooting. Describes common problems that you may

encounter, their possible causes, and their solutions.

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Page xxviiiHow to Use This Book

This guide is intended as a companion to the Release 6.1

System Programming,

and

System Manager’s Guide,

features and procedures in greater detail. Because private networks leverage existing communications system features as well as introducing new ones, this guide focuses not on a thorough discussion of system management and system features but rather on how they apply to private networks. “Related Documents”

on page xxx provide s a complete list of system documentatio n togeth er with

ordering information. In the USA only, Lucent Technologies provides a toll-free customer Helpline

24 hours a day. Call the Helpline at 1 800 628-2888 (consultation charges may apply), or call your Lucent Technologies representative, if you need assistance when installing, programming, or using your system.

Terms and Conventions Used 0

The terms described here are used in preference to other, equally acceptable terms for describing communications systems.

Lines, Trunks, and Facilities

Facility

telephone system and the telephone company central office. Technically, a connects a switch to a switch, for example, the MERLIN LEGEND Communications System to the central office. Technically, a facility or a communications path that does not connect switches, for example, an intercom line or a Centrex line. However, in actual usage, the terms are often applied interchangeably. In this guide, we use

is a general term that designates a communications path between a

Feature Reference

which explain many system

trunk

line

is a loop-start

line

and

trunk

lines/trunks

and

line/trunk

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About This Book

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Page xxixTerms and Conventions Used

to refer to facilities in general. Specifically, we refer to digital specific terms such as When you talk to your local telephone company central office, ask about the terms they use for the specific facilities they connect to your system.

personal line, ground-s tart trunk, DID trunk

Typographical Conventions 0

Certain type fonts and styles act as visual cues to help you rapidly understand the information presented:

Example Purpose

very

It is steps. You before touching the connection.

The part of the headset that fits over one or both ears is called a

If you press the Feature button on an MLX display telephone, the display lists telephone features you can select. A programmed Auto Dial button gives you instant access to an inside or outside number.

Choose screen.

To activate Call Waiting, dial

important that you follow these

must

attach the wristband

headpiece.

([W3URJfrom the display

*11 Constant-width type in italics indicates

Italics indicate emphasis.

Italics also set off special terms.

The names of fixed-feature, factoryimprinted buttons appear in bold. The names of programmed buttons are printed as regular text.

Plain constant-width type indicates text that appears on the telephone display or PC screen.

characters you dial at the telephone or type at the PC.

facilities

, and so on.

. We also use

Product Safety Labels 0

Throughout these documents, hazardous situations are indicated by an exclamation point inside a triangle and the word

WARNING:

Warning indicates the presence of a hazard that could cause death or severe personal injury if the hazard is not avoided.

CAUTION:

Caution indicates the presence of a hazard that could cause minor personal injury or property damage if the hazard is not avoided.

CAUTION

WARNING

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About This Book

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Security 0

Certain features of the system can be protected by passwords to prevent unauthorized users from abusing the system. You should assign passwords wherever you can and limit knowledge of such passwords to three or fewer people.

Nondisplaying authorization codes and marked System Speed Dial numbers provide another layer of security. For more information, see Appendix A,

“Customer Support Information.” Throughout this document, toll fraud security hazards are indicated by an

exclamation point inside a triangle and the words

SECURITYlALERT:

Security Alert indicates the presence of a toll-fraud security hazard. Toll fraud is the unauthorized use of your telecommunications system by an

unauthorized party (for example, persons other than your company’s employees, agents, subcontractors, or persons working on your company’s behalf). Be sure to read “Your Responsibility for Your System’s Security” on the inside front cover of this book and “Security of Your System: Preventing Toll Fraud” in Appendix A, “Customer Support Information.”

SECURITY ALERT

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Page xxxiiHow to Comment on This Book

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Introduction

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Introduction 1

This chapter describes the terminology and concepts that you should understand before you plan and maintain a networked system. It includes the following topics:

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■ Networking Concepts. In simple terms, explains what private

communications networks are, the benefits they offer organizations, and fundamental concepts such as tandem switching and tandem trunking.

■ Tandem Switching and Tandem Trunking. Expands on the definitions of

tandem trunking and tandem switching by showing simple examples of how these features are put into practice in different private network configurations using different types of lines/trunks.

■ Uniform Dial Plan (UDP). Introduces the feature that allows system

managers in a private network to set up a dial plan for reaching extensions at remote networked systems.

■ Centralized V oice Messaging. (Release 6.1 and later systems.) Adds the

capabilities of a centralized VMS/AA in a MERLIN LEGEND Communications system private network.

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Networking Concepts 1

In today’s environment—business, academic, and governmental—many organizations are setting up multiple sites to provide customers and clients with better access to products and services. Branch offices, operations centers, and specialized campuses are supported by technological advances such as local area networks (LANs) and wide area networks (WANs), intranets, the Internet, videoconferencing, and protocols that enable high-speed data communications. For example, banking institutions and insurance companies often consist of a headquarters with branch offices; school systems are organized around a central administrative site that serves several schools in a district. Direct marketing retailers, utilities, and government agencies are dispersed over multiple sites, nationwide or regionally, to reach more clients or customers and to take advantage of the economies offered by specific geographic locations. All of these organizations share a common need: rapid and cost-efficient voice and data communications. For users of the MERLIN LEGEND

Release 6.0 introduces the ability to realize significant savings and convenience benefits through the networking of geographically separate locations in private communications networks. Release 6.1 adds to the savings and convenience benefits by providing a centralized voice messaging capability for networked MERLIN LEGEND systems.

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Communications System,

Briefly, a

private communications network

is an interconnected group of

communications systems, which may consist of MERLIN LEGEND

Communications Systems, DEFINITY

Enterprise Communications Servers

(ECS), and/or DEFINITY ProLogix Solutions. People within each system, called

local users

communications systems in the network, called

, can exchange voice and data with other individuals at

non-local users

. The systems in a private network may be located on the same campus, or they may be separated by thousands of miles.

NOTE:

All MERLIN LEGEND Communications Systems in a private network must be Release 6.0 or later. When centralized voice messaging is used, all MERLIN LEGEND systems that share the centralized voice messaging system must be Release 6.1 or later. While DEFINITY systems can be included in a private network with MERLIN LEGEND systems, the DEFINITY system cannot share the centralized voice mail system of the MERLIN LEGEND system, and the MERLIN LEGEND system cannot share the voice mail system of the DEFINITY system.

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Communications systems are linked by special facilities called These lines/trunks may be analog

tandem tie trunks

tandem Primary Rate Interface (PRI) trunks.

private network trunks

as Private networks are distinct from the

, because they enable private networks.

public switched telephone network (PSTN

As a group, they can be referred to

, T1-emulated tie trunks, or

tandem trunks

of facilities that link customers with central office (CO) service providers across the nation and the world. PSTN lines and trunks allow you to communicate with local and long-distance parties outside your organization.

Private communications networks are not simply communications systems chained together by tandem trunks. They also allow

tandem switching

, which

permits a communications system to route a call from outside a local system to an

outside

facility on a non-local system. In addition, a MERLIN LEGEND

Communications System can route calls from a tandem trunk to a local extension.

NOTE:

In this gui de, purposes of this guide, a

switch

is often used to mean

private network

communications system.

For the

denotes a network with tandem

trunks and tandem switching.

In a private network, correct operation requires that planning be coordinated for all systems. If a private network includes only two systems, this may simply mean that the system managers get together to assure that the correct programming is performed initially, that each manager has a copy of the system forms for the other system, and that the system managers discuss and agree upon any subsequent modifications. In a larger private network, a

manager

should be appointed. This person should keep copies of all system

coordinating system

forms for all systems in the private network. When a change must be made at a local system, it should be cleared through the coordinating system manager, who assesses the change as it affects the private network as a whole. If a change in one system requires modifications in other networked systems, the coordinating system manager ensures that these changes are made.

)

If these terms and concepts are new to you, do not be alarmed. There is no need to comprehend them immediately. You will gain a better understanding as you learn the practical applications of these concepts.

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Benefits of Networking 1

Available for Hybrid/PBX mode systems, the private network features of the MERLIN LEGEND Communications System Release 6.0 and later provide the following advantages for geographically dispersed organizational sites:

■ Toll Savings. Private networked trunks allow you to realize significant cost

savings on toll calls by performing tandem switching in the following two ways:

—Callers on a local system can reach the PSTN via outside trunks

connected to other systems in a private network, avoiding toll charges or substantially decreasing the cost of toll calls. For example, if you are in Cincinnati and another site in your company is in Dallas, you can make a call to a number in the Dallas local calling area over your private network, decreasing toll costs.

—In addition, organizations use private networked trunks to make calls

between networked systems, which may be geographically distant from one another. Using the example above, from your office in Cincinnati you can dial an extension at a sister site in Dallas, just as you would dial an extension on your own local system, without a costly long-distance phone call. You simply dial the extension number.

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■ Service Cost Savings. In addition to toll call savings, there are two other

ways that organizations can save on service costs incurred from telecommunications providers that provide PSTN access:

—You order a point-to-point T1 circuit from a service provider, then use

system programming to set it up for tandem PRI services. As necessary , a service provider provides amplification for PRI tandem trunks in cases where the distance between networked systems is great enough to distort signals, but the service provider does not supply switching services.

—You can tailor your use of PRI B-channels with drop-and-insert

equipment that allows fractional use of T1 channels for non-MERLIN LEGEND data/video communications between sites, while keeping the remaining T1 channels for PRI voice or data traffic.

NOTE:

The 24th T1 channel must not be dropped before reaching the MERLIN LEGEND Communications System because MERLIN LEGEND uses the 24th channel as the PRI D-channel or signalling channel.

—You can tailor your use of T1 channels to support a mix of T1-emulated

tandem tie trunks for voice or data communications at 56 kbps per channel, allowing 2B data transfers at 112 kbps. The system also allows fractional use of point-to-point T1 tandem trunks with drop-and-insert equipment.

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■ Improved Efficiency. In Release 6.1 and later systems, you can save on

resource costs, enhance customer service, and improve productivity in the following ways:

—Coverage and overflow calls can be sent to a remote system using

calling groups, increasing the number of coverage points and allowing sharing of personnel and resources between systems.

—A centralized VMS/AA provides additional savings by eliminating the

need for a voice messaging system at each location in the private network.

—A centralized VMS/AA improves productivity and communications by

allowing users to forward and broadcast messages regardless of location.

—Calls can be forwarded to a non-local extension providing mobility to

personnel around the private network.

—Personal messages can be retrieved from anywhere in the private

network using the same method and extension.

—Incoming calls on any line type at any system can be routed to another

system for improved customer service and reduced customer calling expense.

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Tandem Trunking and Tandem Switching1

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The term

tandem switching

describes the process of routing an incoming call over an outgoing tandem trunk or PSTN facility. If the outgoing trunk is a tandem trunk, it connects to another system in a private network. When the call terminates at an extension on a non-local system, it is an

intersystem call

. Release 6.0 provides enhanced underlying capabilities to satisfy recommended levels of voice and data quality over tandem trunks in a private network.

A tandem-switched call does not necessarily terminate at another system that is directly connected to your own. It may travel over the private network to yet another networked system. Furthermore, a non-local system may direct the call to a PSTN facility and then to someone located outside the private network.

For example, from a system in Minneapolis, a long-distance call to an outside party in Boston can be routed over private tandem trunks to another system in Chicago and then to a system in Boston, resulting in a local call. This routing requires that the private network sites be connected using either a

delay-start

tie line (analog or T1-emulated) or a digital T1 circuit that has been programmed for PRI.

Figure 1–1

shows one way that systems can be connected in a private network.

NOTE:

All of the figures in this chapter use the following conventions:

■ A solid line represents a tandem trunk that connects one system in a

private network to another system in a private network.

■ A dashed line represents a facility that carries a call to the PSTN.

■ A square labeled ML indicates a MERLIN LEGEND

Communications System.

■ A rounded rectangle labeled DE F indicates a DEFINITY ECS or

DEFINITY ProLogix Solutions system.

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Public Switched Telephone Network (PSTN)

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ML A

New York, NY

PRI

4321

ML B

Chicago, IL

Ext.

Figure 1–1. Series Configuration

To make a call from System A to System C, a user at Extension 4321 dials reach Extension 3699. The call travels over tandem trunks through System B to System C withou t using the PSTN to pr ovide switc hing serv ices. Syst ems B and C

series configuration

in this Using another aspect of tandem switching, the user at Ext. 3699 employs

Automatic Route Selection (ARS) normally in order to dial a number in the New York area code,

912125551234, for example, where 9 is the ARS code. In this case,

the call is routed from System C to System A over tandem trunks. At System A, the call goes out over a facility connected to the PSTN as a local call from System A.

These two calls have the following features in common:

PRI

Los Angeles, CA

Ext.

5455

are called

ML C

Tie

tandem switches

ML D

Santa Monica, CA

Ext.

3699

Ext.

6233

3699 to

■ All or part of each call is carried over tandem trunks.

■ The calls are routed seamlessly from a system extension to a destination.

■ The calls can result in substantial savings over the cost of the same calls

using telecommunications service providers and the PSTN.

■ The users dial the calls normally: one is an inside call and one is an ARS

call made on a System Access (SA) button. ARS and Universal Dial Plan (UDP) routing are programmed to take advantage of all PSTN facilities in the network.

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In the next sections, we will look at this and other private network configurations and examine more carefully the tandem trunks that link systems in private networks.

Network Configurations 1

This topic looks at some sample private network configurations and the differences among them. It does not illustrate networks can be connected.

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Page 1-8Tandem Trunking and Tandem Switching

all

of the possible ways that private

Issue 1

Figure 1–1

arranged in a line with no central system acting as a hub. In Figure 1–1 A and D are

, as noted above, shows a series configuration, where systems are

, Systems

peripheral

systems, because neither connects to more than one switch in the private network. Note that a series configuration can consist of only two systems.

Figure 1–2

star configuration

PSTN

shows the second possible arrangement for private networks, called a

PSTN

ML A

PRI

ML C

DEF E

PRI

ML B

PSTN

Figure 1–2. Star Configuration: Five Systems

PRI

ML D

PSTN

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In this example, system users make calls in the same way as they would in a series configuration. The primary difference between a star configuration and a series configuration is that in a star configuration all network-routed calls pass through a central

hub system

, in this case, a DEFINITY ECS or DEFINITY ProLogix Solutions system. The hub normally terminates stations as well as external facilities.

PSTN

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Page 1-9Tandem Trunking and Tandem Switching

ML C

Call 2

PRI

Call 1

T1 DID

PRI

ML B

Figure 1–3. Star Configuration: Three Systems

Figure 1–3

shows a simpler star configuration consisting only of MERLIN LEGEND Communications Systems. It may look like a series, but all networkrouted calls pass through a central hub, System A, just as they do in the larger star configuration. This illustration also shows how PSTN calls can be routed in a private net work.

Figure 1–3

shows some specific PSTN facilities as well as tandem trunks. Calls 1 and 2, represented by dotted lines, can enter the private network and be routed directly through System B to extensions on System C and System A. Both Direct Inward Dialing (DID) and PRI outside facilities permit this type of routing. However, the types of tandem trunks that connect the systems, as well as the lines/trunks connecting to the PSTN, also affect the decisions that you make

PRI

ML A

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about private network configurations. In the next topic, we will revisit all three of these configuration diagrams.

Lines and Trunks 1

The types of tandem trunks that connect systems in a private network, as well as the types of facilities that connect systems to the PSTN affect the performance and available features in a private network. This topic examines the distinctions among trunks and the important decision factors that you must consider when you set up your private network. It also discusses the advantages and disadvantages of the configurations we looked at in the previous section.

Tandem PRI facilities have numerous advantages over the tandem T1-emulated or analog tie trunks that can link systems in a private network. Table 1–1

summarizes the differences. In Chapter 2, “Call-Handling Scenarios,” you will learn more about the details of the features that are noted here.

NOTE:

Centralized Voice Messaging is available for Release 6.1 and later systems only. For Release 6.0 systems, disr egar d the Cent rali zed Voice Messaging capability in the following topics because each system must have its own voice messaging applic ation.

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Table 1 –1. Tandem PRI Trunks versus Tandem Tie Trunks

Feature PRI Tie Differences

Intersystem calling

For intersystem calls, the caller’s extension label and extension number can be displayed at recipient’s MLX (and some DEFINITY) display telephones across the network.

Manual intersystem transfers across the private network return to the originator when the intended destination is busy or has Do Not Disturb on and no call coverage path available.

Dial-plan routing of calls on incoming PSTN PRI trunks across the private network.

Automatic Number Identification (ANI) and Incoming Caller ID (ICLID)

Routing of PSTN DID calls across the network.

128-kbps 2B data video and data exchange across the network.

Optimal transmission quality for calls routed across two or more systems in a private network.

✔✔ ✔

✔

✔✔

✔

✔✔

✔

✔✔

PRI provides faster call setup.

Calls that cross tandem tie trunks are displayed as outside calls.

When a call is transferred manually across the network on tandem tie facilities, the call does not return in the event that the intended destination is busy . The origi nal caller m ust call ba ck in order to speak with someone.

PRI provides faster call setup.

Information is conveyed across the network on tandem PRI trunks , not on tie trunks.

Tie trunks support only 14.4 kbps . T1emulated tie trunks programmed for data can only support up to 112 kbps.

T o ensure adequ ate transmissio n quality , no more than two spans of analog tandem tie trunks can be provided between switches in a series configuration (or 3 including transfers and coverage). Also, for long loops of analog tandem tie trunks between switches, you may need to contact the PSTN servi ce provider to adjust the amplification.

Transmission quality on PRI and T1 tandem trunks are the s am e. Up to ei ght tandem PRI and/or T1 trunks can be used in a series configuration providing optimal transmissio n qual ity. However , T1 tandem trunks may cause call setup delays.

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Touch Tone Receivers None

Centralized Voice Messaging

■ Call information indicating

✔

inside call

■ Message Waiting light updates

✔✔

The advantages of tandem PRI facilities are illustrated in practical terms in

Chapter 2, “Call-Handling Scenarios.” However, tandem PRI trunks do present the following challenges that affect your configuration planning.

Required for all calls routed across the

✔

private network on tie trunks. (Voice messaging increase s tr af f ic in both directions.) Not required on PRI trunks.

With PRI, the call information signals sent by the remote system to the centralized VMS indicates inside calls. With tie trunks, the call information signals for all calls indicates an outside call.

With PRI, the Mess age W aiting li ghts are updated on the signalling D-channel. With tie trunks, Message Waiting lights updates are sent a s se para t e vo ice c alls and must compete with other voice and data calls for an available tie t runk and touch tone receiver. As a result, the Message Waiting light updates may be delayed on tie trunks.

■ Each PRI facility connected to a system, whether it is a tandem trunk or an

outside facility and whether or not drop-and-insert equipment is used between systems, takes up 24 of the 80-line capacity of a MERLIN LEGEND Communications System.

■ Each 800 NI-1BRI module takes up to 16 of the 80-line capacity.

■ Each 400EM tie module takes up to 4 of the 80-line capacity.

In view of this fact and the differences noted in Ta ble 1–1

, we will briefly revi sit the

private network configurations we looked at earlier. The next three figures show basically the same configurations that you saw

before, slightly modified to emphasize the differences among them. The figures shown are only a few examples for illustration, and do not represent all possible configurations. In these figures, the lines and trunks literally represent the number of facilities connected to each system in a given configuration. The PSTN facilities shown here are only examples. You can connect the same types of loop-start, ground-start, T1 Switched 56, DID (Direct Inward Dialing), and T1-emulated analog lines/trunks to a private network system that you can to a non-networked system.

SECURITYlALERT:

Do not connect T1-emulated loop-start lines or analog loop-start lines without reliable disconnect to any switch that is part of a private network.

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NOTE:

In the following example, the PRI tandem trunks are implemented on T1 circuits provisioned for bipolar 8 zero substitution (B8ZS) line code.

PSTN

P R I / 2 4 P R I / 2 4 B R I (1 6 ) P R I / 2 4

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ML A ML B

NY IL

48 lines Intersystem and outside up to 128-kbp s 2B d ata

P R I / 2 4

72 lines Intersystem and outside up to 128-kbp s 2B d ata

Centralized V M S/A A

P R I / 2 4

Figure 1–4. Series Configuration: Four Systems

From a planning perspective, consider the following points about the series configuration illustrated in Figure 1–4

■ System D is linked to the private network by tie lines (a total of 8), so users

at MLX display telephones on System D cannot see the name and/or number of a caller who reaches them from another system in the private network.

■ To ensure proper transmission quality, the path of a private network call

should include no more than two network in Figure 1–4

■ When an outside dial-plan routed PRI call with ANI arrives on System A or

includes one such span, between Systems C and D.

B, ANI calling party information travels to a destination extension on systems connected by PRI tandem trunks (A, B, or C) but not across tie tandem trunks (System D). System D users can receive this information only from their PRI to the PSTN.

ML C

CA CA

48 lines Intersystem 128-kbps 2B d a ta ; o u ts id e up to 128-kbp s

2B d ata

Tie / 4

spans

of analog tie trunks. The private

ML D

32 lines Outside 128-kbps u p to 2B d ata VM S

■ System D is located in close geographic proximity to System C. This allows

System D to use the PSTN for 2B video calls with System C at up to 128 kbps without incurring high toll costs. However, because of the tie connections, intersystem video and intersystem high-speed data calls are not supported to and from System D.

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■ In this configuration, System B uses more of its 80-line capacity for private

network trunks than do Systems A, C, and D.

■ A centralized VMS/AA is installed on System B. Voice mail and automated

attendant services can be used by extensions and calling groups on Systems A, B, and C. Since Systems A and C are connected to System B via a PRI tandem trunk, Message Waiting light updates are sent over the signalling D-channels. The call information signals sent by Systems A and C to the centralized VMS/AA on System B allow the centralized VMS/AA to differentiate between inside and outside calls. Some applications (such as Intuity AUDIX) use the information to play different personal greetings recorded by users for inside and outside callers.

■ Since System D is not directly connected by a tandem trunk to System B,

System D must have its own local voice mail system and automated attendant.

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The configuration illustrated in Figure 1–4

, with its advantages and disadvantages, is suitable for many businesses, particularly when one or more systems do not require PRI features. For example, a system linked by tandem tie trunks may be perfectly adequate for a warehouse or other operations group.

PSTN

PRI

ML C

PRI

ML A

ML B

Figure 1–5. Star Configuration: Three Systems

PRI

V o ic e M a il/A u t o A tt e n d a n t

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In Figure 1–5, the 3-system star configuration that we saw earlier has been

modified to bring out some additional possibilities for private network configurations. Consider the following points as you review this graphic:

■ All three systems are Release 6.1 or later systems and enjoy the

advantages of tandem PRI trunks, including MLX telephone display capabilities and high-speed data communications among networked systems.

■ System B is a corporate data-processing center with no facilities connected

to the PSTN. It is located in the same building as System A. Outside calls for System B arrive at Sy stem A. All inter system ca lls pass th rough Sys tem A, the hub system.

CAUTION:

Unless networked systems are co-located, each system should have at least one loop-start line connected to the PSTN. The line is required to allow connection of a power-failure tel epho ne to the Power-Failure Transfer (PFT) jack on a module as a power outage backup and for correct routing of emergency and other N11 (91 1, 41 1, etc.) calls. To ensure that the correct services are reached, if the loop-start line is used for emergency or other N11 calls, it should be assigned to the main pool. In this case, inter-exchange (IXC) calls determine the number of loop-starts required. Refer to

Reference

guide for details on the PFT feature.

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Feature

■ PRI dial-plan routed calls arrive at System C, where they are routed to a

telemarketing calling group on System A. These agents primarily use the outside PRI facility connected to their system to return customer calls.

■ Both System B and System C share the voice mail/automated attendant

application connected to System A. Calls are routed from the automated attendant to users on all these systems.

NOTE:

For Release 6.0 networks, Centralized Voice Mail is not available. Each system must have its own voice mail application for voice mail coverage. However, with Release 6.0 Version 11 and later systems, calls can be routed over the private network from a centralized automated attendant.

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PSTN

ML A

PRI

DEF E

PRI

ML B

PSTN

Figure 1–6. Star Configuration: Five Systems

PSTN

ML C

PRI

ML D

PSTN

Figure 1–6

again shows the star configuration we looked at earlier in this chapter. All systems enjoy the advantages of PRI tandem trunks, which are made possible in this larger private network by the greater line capacity of the hub DEFINITY ECS or DEFINITY ProLogix Solutions, System E. In this private network, the systems may be spread across thousands of miles and realize considerable toll savings on intersystem calls and long-distance ARS calls. Although not shown, each system has its own voice mail/automated attendant system because the MERLIN LEGEND systems and the DEFINITY system cannot share voice messaging sys tems.

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Software Defined Network (SDN) Configu rat ion 1

Support for AT&T’s Software Defined Network (SDN) was first offered with MERLIN LEGEND in Release 2.0. Release 4.2 introduced support for VNET, MCI’s version of SDN.

NOTE:

Sprint offers VPN Premiere; this virtual network is not supported by MERLIN LEGEND.

With Release 6.0 and later systems, UDP routing via 3-, 4- or 5-digit dialing offers SDN customers simplified dialing. An SDN dialing plan identifies all network locations with a dialing plan of up to 10 digits. Users at all locations in the private network can be identified with 3- or 4-digits (unique). This uniqueness criteria may require some users whose last 3- or 4- digits are identical to change their numbers.

For example, if each MERLIN LEGEND in the private network is configured with a 4-digit dial plan, the routing patterns can be set up to prepend the digits needed to support an SDN 7- or 10-digit dialing plan. To support the 7- digit dial plan, four digits must be prepended; to support the 10-digit dial plan, six digits must be prepended. This configuration must be coordinated with the SDN/VNET provider.

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PSTN

Pool 71

ML A

841-6173

Tie/PRI

Figure 1–7. Software Defined Network (SDN) Configuration

SDN

ML C

731-2162

ML B

957-4013

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Figure 1–7 shows three MERLIN LEGEND systems in an SDN network. On

System A, the SDN trunks are assigned to pool 71. A user on System A calling the user on System B dials 4013, the last four digits of the SDN number 957-4013. System A routes the call using trunk pool 71 and prepends the digits 957. Similarly, a user on System A calling the user on System C dials 2162. System A routes the call using trunk pool 71 and prepends the digits 731.

The SDN can also be used for all of the toll calls as well as the calls within the SDN. Any 10-digit number from MERLIN LEGEND users that does not fall within the SDN numbering plan for the customer is routed over the PSTN (see Figure

1–7). This is a standard feature of SDN.

Considerations 1

■ Whether you are transferring calls to a non-local extension over the Public

Switched Network or an SDN, you must program the MERLIN LEGEND to support trunk-to-trunk transfer.

NOTE:

Trunk-to-trunk transfer is not allowed when the line/trunk with the incoming call is a loop-start line that is not programmed for reliable disconnect.

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SECURITYlALERT:

Any changes to the trunk-to-trunk transfer setting (especially for voice messaging ports or remote access ports) must be considered carefully in

order to minimize the potential for toll fraud. See Appendix A “Customer Support Information” for security information.

■ For Release 6.1 and later systems, Centralized Voice Messaging is not

supported in an SDN environment.

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Uniform Dial Plan 1

The private network benefits that we looked at earlier in this chapter are possible

through the combination of core system features—primarily Automatic Route Selection (ARS), Remote Access, and PRI support—and two additional features designed specifically for private networks:

■ the non-local dial plan, which is part of the Uniform Dial Plan (UDP). UDP

can route calls over the private network, SDN, or PSTN.

■ the Group Calling enhancement, which allows assignment of a non-local

UDP extension as a calling group member. (This feature is available for 6.1 or later systems. )

The use and management of all these features is discussed in Chapters 2, 3, 4, and 5.

This topic presents an overview of how the private network takes advantage of the non-local dial plan feature.

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Each switch in the private network has both a local dial plan and a non-local dial plan that together form the UDP. The local dial plan is set up at the local system as in earlier releases, using System Renumbering. The non-local dial plan is a list of up to 50 different extension number ranges for other systems in the private network. When users call one another, the system searches the local dial plan; if the extension number is not found, it consults the non-local dial plan and associated routing information in order to send the call directly or indirectly to another system in the private network. Routing information is programmed into as many as 20

patterns

consisting of routes. Routes specify pools, voice/data call

type, and FRLs similar to those used for ARS.

NOTE:

In releases, prior to 6.0, intersystem calls were made by dialing a pool access code followed by the extension number. With Release 6.0 and later systems, the process is simplified by the UDP ranges and routing patterns programmed on the local system so that the system can find non-local extensions and direct calls to them. Actual system numbering is always performed at the local system.

The diagram shown in Figure 1–8

gives an example of the systems in a private network consisting of a MERLIN LEGEND Communications System in New Jersey, another in Illinois, and a third in California. It resembles the private network shown in Figure 1–3 on page 1–9

. A caller picks up a telephone at Extension 1000 in New Jersey and dials Extension 3400 to reach a co-worker at the California location. The New Jersey system searches the local dial plan for Extension 3400.

Because Extension 3400 is not located on the New Jersey system, that system checks the non-local dial plan to find the extension number. The non-local dial

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plan has two sets of extension ranges, both of which include routing information that directs the call to the same private network trunk. This tandem PRI trunk connects the New Jersey system to the Illinois system. In the non-local dial plan, one extension range specifies the extensions on the system in Illinois, while the other includes the extensions on the system in California.

When the call reaches the Illinois system, that system also checks the local dial plan and then the non-local dial plan. It routes the call over a second tandem PRI trunk to the California system. The system in California searches its local dial plan, finds a match, and directs the call to Extension 3400.

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x1000 x2030 x3400

Local

Dial Plan

1000

1037

Non-Local

Dial Plan

2020

2071 3200

3459

LEGEND NJ

PRI PRI

Local

Dial Plan

2020

2071

Non-Local

Dial Plan

1000

1037 3200

3459

LEGEND IL

Local

Dial Plan

3200

3459

Non-Local

Dial Plan

1000

1037 2020

2071

LEGEND CA

Figure 1–8. Uniform Dial Plans

Each system has its own local system operator, and dialing the local switch. Users can reach an operator on another private network system

by dialing that operator’s extension number. Alternatively, Listed Directory Number (LDN) calls from one system to another private network system can be routed to the destination system’s Queued Call Console (QCC) operator.

0 calls the operator on

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In the next chapter, we look at planning and setting up dial plans across a private network, as well as the use of routing and other system management features.

Centralized Voice Messaging System 1

In Release 6.1 and later, MERLIN LEGEND Communications Systems connected in a private network by tandem trunks may share a centralized voice and fax messaging system and automated attendant (VMS/AA). The centralized VMS/AA is connected to one of the MERLIN LEGEND systems which is then known as the

“VMS hub” system. “Remote” MERLIN LEGEND systems which are directly connected to the “VMS hub” system by tandem trunks can then share the Centralized VMS/AA.

Coverage and overflow calls using calling groups from the VMS hub and any of the remote systems can be sent to the centralized VMS/AA. System users retrieving voice mail can call the same number from any location and be directly connected to the centralized VMS/AA. The centralized VMS/AA updates Message Waiting lights across the private network for its subscribers on remote systems.

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NOTE:

A private network can include more than one VMS hub with a centralized VMS/AA system. Each system in the private network may also have local VMS/AA systems.

However, a single exte nsion can have only one

voice mailbox.

Configuration Requirements 1

A centralized VMS/AA is subject to the following configuration requirements and constraints:

■ A DEFINITY ECS or DEFINITY Prologix

VMS/AA with a MERLIN LEGEND system.

■ The VMS hub system and all remote systems sharing a centralized

VMS/AA must be MERLIN LEGEND Release 6.1 or later systems.

■ Each MERLIN LEGEND system must be configured as Hybrid/PBX.

■ Networked MERLIN LEGEND systems that are not directly connected to

the “VMS hub” system (more than one span away) cannot share the centralized VMS/AA.

■ More than one centralized VMS/AA can be configured in a single private

network. These centralized VMS/AA systems can share a VMS hub, or have separate VMS hubs.

cannot

share a centralized

■ Any MERLIN LEGEND system in a private network may also have a local

VMS/AA system that is not shared.

■ Each extension in the system can have

only one

voice mailbox, no matter

how many VMS/AA systems are available.

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■ Only the following voice messaging systems are supported for centralized

VMS/AA:

■ MERLIN LEGEND Mail

■ Messaging 2000

■ Intuity AUDIX

■ IS-III AUDIX Voice Power (no longer orderable)

■ A Uniform Dial Plan (UDP) must be established for the private network.

■ All trunks within the private network should have unique trunk numbers.

This allows the centralized VMS/AA to provide different call handling and/or greetings based on the trunk on which the call was received.

■ No more than three (3) analog spans should be involved in any call or

volume levels may not be adequate. Multiple spans may be the result of transfers and coverage. If more than three spans may be involved in call completion, digital rather than analog spans should be used.

■ Sending overflow or coverage calls to a centralized VMS/AA may add

unanticipated traffic to a private network. A call transferred from one system to another and then sent back by overflow or coverage occupies two private network trunks. The MERLIN LEGEND system does not provide release link operation when a call through the private network returns to the originating system.

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■ Pools within a UDP route cannot mix PRI and tie tandem trunks. The type

of signaling is based on the first trunk in the pool, and will not work correctly for subsequent trunks if they are not the same type.

■ If tandem tie trunks are used, touch tone receivers (TTR) are required at

the hub system and at each remote system for each call (including coverage calls) and for message-waiting light updates over the tie trunks. Voice messaging increases traffic in both directions.

Tandem Facilities 1

MERLIN LEGEND systems are connected by tandem trunks. Tandem trunks may be tie trunks or PRI trunks:

■ A tie trunk may be analog (E & M) or digital (T1). An analog tie trunk carries

a single voice call channel. A digital (T1 or fractional T1) tie trunk carries up to 24 voice call channels using a digital encoding scheme. Both use inband signalling.

■ A PRI tandem trunk is a point-to-point T1 circuit programmed in the

MERLIN LEGEND systems at both ends as ISDN Primary Rate Interface (PRI). It consists of 23 B-channels for voice calls (digitally encoded) and 1 D-channel (channel 24) for digital signalling information.

The type of tandem trunk used (PRI or tie) has an effect on the operation of the centralized VM S/AA system.

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■ When a user receives and outside call and the call goes to coverage by a

centralized VMS/AA using either tie or PRI tandem trunks, the call information signals sent to the centralized VMS/AA indicate an outside call.

■ When a user calls a local extension and the call goes to coverage by a

centralized VMS/AA using either tie or PRI tandem trunks, the call information signals sent to the centralized VMS/Aa indicate an inside call.

■ When a user calls a non-local extension and the call goes to coverage

across the private network:

—If a tie tandem trunk is used to route the original call or to route the

coverage call over the private network to the centralized VMS/AA, the call information signals sent to the centralized VMS/AA indicate an outside call.

—If an all PRI routing is used, the call information signals sent to the

centralized VMS/Aa indicate an inside call.

This ability to differentiate between inside and outside calls is used by some VMS/AA applications to provide:

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■ different greetings

■ inform the receiver who called

■ record a reply to the caller or return a call to the caller

Implementation of Centralized VMS/AA 1

Centralized VMS/AA is implemented using the Group Calling enhancement and UDP routing. Integrated VMI calling groups are defined on the VMS hub system and each remote system.

From the user’s point of view, the routing is transparent. The user dials the same extension number from any location in the private network to reach the voice messaging sys tem.

The integrated VMI calling group on the VMS hub system contains the voice messaging system ports. The integrated VMI calling groups on each remote system receive overflow, coverage, and voice mail retrieval calls and route them to the integrated VMI group on the VMS hub system.

Routing to the centralized VMS/AA is done by assigning a single non-local extension as a member of the integrated VMI calling group at each remote system sharing the centralized VMS/AA. This extension has no corresponding physical extension and is referred to as the

VMI conversion number

in this guide.

NOTE:

The VMI conversion number should not be published. This prevents users from dialing the VMI conversion number to retrieve messages, which can result in improper operation of the VMS/AA application.

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For information about centralized voice message programming, please see:

“Centralized Voice Messaging Programming” in Chapter 5. For information about centralized automated attendant programming, please see: “Centralized Automated Attendant Programming” in Chapter 5.

Example 1

For the purposes of this example, refer to Figure 1–9. A caller dials Extension 1234, a local extension on System B. Extension 1234 is assigned to a coverage group programmed as an integrated VMI group (Extension 7771 with one nonlocal member, extension 5528) as the receiver. The user at Extension 1234 is not available and the call is directed to integrated VMI calling group 7771. The systems checks the local dial plan then the non-local dial plan for the VMI calling group member extension (5528). Using UDP routing, the system absorbs the 4 dialed digits (5528) and prepends the digits 7771 (the extension for the centralized VMS/AA at the VMS hub) then routes the call over the PRI tandem trunks to the centralized VMS/AA.

If the caller leaves a message, the centralized VMS/AA sends signals over the signalling D-channel and the Message Waiting light at extension 1234 goes on. When the user at extension 1234 dials 7771 to reach the centralized VMS/AA to retrieve messages, the same routing takes place as before and when all messages are retrieved, the centralized VMS/AA sends signals over the signalling D-channel to turn off the Message Waiting light at Extension 1234.

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PRI

ML A

Integrated VM I

x7771

(V M S voice ports)

V o ic e M a il/A u to A tt e n d a n t

ML C

Integrated VM I

x7771

(one non-local m em ber)

PSTN

PRI

ML B

Integrated VM I

x7771

(one non-local m em ber)

PRI

Figure 1–9. Centralized Voice Mail with one VMS/AA for Entire Network

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NOTE:

It is recommended that PRI lines, rather than tie lines, be used between MERLIN LEGEND Communications systems in a private network that utilizes the Centralized Voice Mail feature. Refer to Table 1–1, page 1-11

for advantages of PRI lines.

Because tandem switching allows intersystem coverage of calls to other systems on the private network, it is important to note that coverage to the centralized VMS/AA from remote private network systems must be limited to only one span. This means that a call may only pass through one tandem trunk to the centralized VMS/AA on the hub system.

It is also important to note that if a DEFINITY ECS or DEFINITY Prologix Solutions system is a networked system, it can not receive coverage to the centralized VMS/AA. Also, if the DEFINITY ECS or DEFINITY Prologix Solutions is the hub system in the star configuration, a centralized VMS/AA servicing connected MERLIN LEGEND Communications systems is not possible.

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It is also possible to have more than one centralized VMS/AA on different hubs, and also have local VMS/AA systems attached to individual MERLIN LEGEND systems. However, each extension in the private network can have only one voice mailbox.

For Release 6.0 networks, Centralized Voice Mail is not available. Each system must have its own voice mail application for voice mail coverage. However, with Release 6.0, Version 11, calls can be routed over the private network from a centralized automated attendant.

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Networking Voice Messaging Systems 1

DEFINITY ECS and DEFINITY Prologix systems cannot share a MERLIN LEGEND system centralized VMS/AA, and MERLIN LEGEND systems cannot share a DEFINITY system VMS/AA. Networking voice messaging systems is an alternative that provides the appearance to users that everyone is sharing a single VMS.

Lucent Technologies messaging systems that support networking are Intuity AUDIX and Messaging 2000. Please see the messaging system documentation for more information about networking capabilities.

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Figure 1–10

Systems A and B networked to the VMS/AA system on DEFINITY System C.

shows a shared centralized VMS/AA used by MERLIN LEGEND

PRI

ML B

PRI

DEFINITY C

PRI

ML A

Centralized VMS/AA

Intuity AUDIX

VMS/AA

Intuity AUDIX

Figure 1–10. Networked Voice Mail Systems

Dedicated

Digital Circuit

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Call-Handling Scenarios 2

This chapter helps you plan and understand private network configurations. It includes the following two main topics:

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■ Networking Guidelines. This section describes the factors that you must

consider when planning a private network or managing one or more systems in an existing private network.

■ Network Configuration Scenarios. This section illustrates generally how

systems can be set up and how calls can be made and received in several example pr ivate network configurations. “Scenario 2: Two Systems,

Tandem Tie Facilities,” provides a descriptive business example that helps you see how private network features work in a real-world business.

T o help you plan further and understand your private network, Chapter 3, “Feature Interactions,” summarizes the ways that features work in private networks. Security issues are discussed in depth in Chapter 4, “Security,” and you should read this chapter in order to fine-tune such settings as Facility Restriction Levels (FRLs) for Automatic Route Selection (ARS), extensions, Uniform Dial Plan (UDP) ranges and routing, Remote Access, and extensions.

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Networking Guidelines 2

This topic outlines general planning and setup considerations for networked systems, providing the information that you need in order to understand the sample private network scenarios presented in the next section of this chapter.

Security issues are discussed in greater detail in Chapter 4, “Security,” and in Appendix A, “Customer Support Information.”

When systems are networked, follow these guidelines in order to make implementation of private network features go smoothly. These guidelines are based on the assumption that you plan to use the features listed below. Therefore, a coordinating system manager to oversee network -affecting changes is recommended.

■ Non-local dial plan for intersystem calling among extensions located on

different systems on the private network

■ ARS dialing via private networked trunks to allow users in one system

to access the public switched telephone network (PSTN) facilities connected to one or more other networked systems

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■ UDP routing for intersystem calling and ARS use of tandem trunks

Whether you are working alone to manage multiple systems in a private network or working with others who manage other systems in a private network, the overall planning considerations affect all networked systems.

The following topics do not explain programming procedures or details of all system features that the sections reference. For detailed feature information, see

Feature Reference

the

Programming

. For detailed programming procedures, see

Non-Local Dial Plan 2

System managers in a private network create non-local dial plans so that local system users can call extensions in remote networked systems. This

is transparent to system users; they dial these calls as though they were

dialing

intercom calls, using System Access (SA) or Shared System Access (SSA) buttons. Chapter 5, “Network Management parameters as the valid number of digits, extension ranges, and patterns for programming non-local dial plans and routes.

A non-local dial plan consists of extension numbers for the following:

■ Stations

,” includes information about such

System

intersystem

■ Adjuncts

■ Listed Directory Number (LDN)

■ Remote Access

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When setting up your private network for intersystem calling, keep the following important points in mind:

■ You cannot program the local ARS access code or pool dial-out codes into

non-local dial plan extension ranges; the system blocks this programming. Non-local extension range numbers cannot begin with the local ARS access code. If, for example, the ARS access code begins with 9 and a

non-local dial plan extension range is 9230–9330, programming is blocked. You must not program the ARS access code of a non-local system into the non-local dial plan because it poses a security risk; it is best if all networked systems assign the same ARS access code. For more information, see

“Automatic Route Selection (ARS)” on page 7

■ The Remote Access codes of non-local systems can be included in the

non-local dial plan for the convenience of technicians for technical support or for users to program their forwarding home extensions on a non-local system. Each system should have a unique and unambiguous Remote Access code. For more information, see “Remote Access” on page 8

■ Your non-local dial plan programming has no effect on the remote

system(s) it references. Local dial-plan changes made at a system do not automatically update the non-local dial plan numbering plans of networked systems. To avoid misrouting, it is recommended that manual adjustments to the non-local dial plans made by private network system managers be made at the same time. System managers should provide ranges wide enough to avoid problems in future non-local dial plan changes.

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■ In most cases, the extension numbers programmed into the non-local dial

plan should be the same extension numbers that users at remote systems dial in order to reach one another within their systems. The main exception occurs when non-local dial plan numbers refer to extensions on DEFINITY Enterprise Communications Server (ECS) or DEFINITY ProLogix Solutions systems, which include five digits. See “Non-Local DEFINITY ECS or

DEFINITY ProLogix Solutions Systems” on page 6 for details.

■ Extensions included in ranges must be unique and

systems. In other words, if the local system includes extension

unambiguous

112

across

, that

system blocks the programming of a non-local extension range that

112

encompasses extension

2. If it allowed the range, calls to 1122 would be misrouted because the system would send calls for extension 1122 to extension 112 as soon as it received the first three numbers. In this example, the local system prevents the numbering conflict. However, if the local system is connected to more than one other networked system, programmed extension ranges must assure proper routing. For example, if the manager on System A must program extension ranges on two connected systems, System B and C, the specified ranges on Systems B and C must be unique and unambiguous. If System B includes the range 2030–2049, System C cannot include an extension range that encompasses either extension 203 or extension 204.

■ MERLIN LEGEND Communications System dial plans may include 2-digit,

3-digit, or 4-digit extension numbers. However, DEFINITY ECS or DEFINITY ProLogix Solutions users must dial four digits in order to reach a

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MERLIN LEGEND Communications System extension in a private network. Although the MERLIN LEGEND Communications System can be programmed to drop digit(s), it is recommended that in networks with DEFINITY ECS or DEFINITY ProLogix Solutions use 4-digit dial plans. The next topic provides additional details.

■ When planning non-local extension ranges, Primary Rate Interface (PRI)

dial-plan routing and Direct Inward Dialing (DID) numbers must be considered. If calls are routed across the private network to these numbers, they also must not conflict with extension ranges in other private network systems. In addition, UDP routes must specify correct digit manipulation (deleting or adding digits). When such calls are routed to 5-digit DEFINITY ECS or DEFINITY ProLogix Solutions systems, special considerations apply. See the next topic for details.

■ A centralized VMS/AA is subject to the following configuration

requirements and co nstra in ts:

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—A DEFINITY ECS or DEFINITY Prologix

cannot

share a centralized

VMS/AA with a MERLIN LEGEND system.

—The hub system and all remote systems sharing a centralized VMS/AA

must be MERLIN LEGEND Release 6.1 or later systems. —Each MERLIN LEGEND system must be configured as Hybrid/PBX. —Networked MERLIN LE GEND syste ms that are no t direc tly conne cted to

the “hub” system (more than one span away) cannot share the

centralized VMS/AA. —More than one centralized VMS/AA can be configured in a single private

network. More than one centralized VMS/AA can be installed on a single

MERLIN LEGEND system. —Any MERLIN LEGEND system may also have a local VMS/AA system

that is not shared. —Each extension in the system can have only one voice mailbox, no

matter how many VMS/AA systems are available. —Only the following voice messaging systems are supported for

centralized VMS/AA:

■ MERLIN LEGEND Mail

■ Messaging 2000

■ Intuity AUDIX

■ IS-III AUDIX Voice Power (no longer orderable)

—A Uniform Dial Plan (UDP) must be established for the private network. —All trunks within the private network should have unique trunk numbers.

This allows the centralized VMS/AA to provide different call handling

and/or greetings based on the trunk on which the call was received.

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—No more than three (3) analog spans should be involved in any call or

volume levels may not be adequate. Multiple spans may be the result of

transfers and coverage. If more than three spans may be involved in call

completion, digital rather than analog spans should be used. —Sending overflow or coverage calls to a centralized VMS/AA may add

unanticipated traffic to a private network. A call transferred from one

system to another and then sent back by overflow or coverage occupies

two trunks. The MERLIN LEGEND system does not provide release link

operation when a call through the private network returns to the

originating system. —Pools within a UDP route cannot mix PRI and tie tandem trunks. The

type of signaling is based on the first trunk in the pool, and will not work

correctly for subsequent trunks if they are not the same type. —If tandem tie trunks are used, T ouch T one Receivers (TTRs) are required

for each call over the tie trunks including voice calls, coverage calls, and

Message Waiting light updates. These calls go both directions, so TTRs

are required at both ends. —Centralized VMS/AA is implemented using the Group Calling

enhancement and UDP routing. Integrated VMI calling groups are

defined on the hub system and each remote system. The integrated VMI

calling group on the hub system contains the voice messaging system

ports. The integrated VMI calling groups on each remote system receive

overflow, coverage, and voice mail retrieval calls and route them to the

integrated VMI group on the VMS hub system.

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—Routing to the centralized VMS/AA is done by assigning a single non-

local extension as a member of the integrated VMI calling group at each

remote system sharing the centralized VMS/AA. From the user’s point of

view, the routing is transparent. The user dials the same extension

number from any location in the private network to reach the voice

messaging system. This extension has no corresponding physical

extension and is referred to as the

VMI conversion number

in this guide.

NOTE:

The VMI conversion number should not be published. This prevents users from dialing the VMI conversion number to retrieve messages, which can result in improper operation of the VMS/AA application.

■ A PassageWay Telephony Services application may use the length of

ANI/ICLID information to differentiate outside calls from inside calls. Some businesses can set up their PBX to send only a 4-digit number for ANI/ICLID information. For Release 6.0 and later systems, a call with less than 5 digits appears as a private network call.

■ If a PassageWay Telephony Services application uses the presence of a

trunk identifier to differentiate inside and outside calls, a non-local dial plan call displays as an outside call. The display depends upon the application.

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Non-Local DEFINITY ECS or DEFINITY ProLogix Solutions Systems 2

DEFINITY ECS and DEFINITY ProLogix Solutions communications systems can support either 4- or 5-digit dial plans. However, 5-digit extension ranges cannot be programmed into a MERLIN LEGEND Communications System non-local dial plan. With possible extension numbering conflicts in mind, handle 5-digit extension numbers by using one or both of the two methods explained below.

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■ Program the

first

four digits of the extension number ranges into the non-

local dial plan, for example 1234–1236 for remote extensions 12340–12369. Because ranges are programmed and not necessarily individual extensions, this may not present problems. However, this method does not work when you need to stipulate ranges of fewer than ten numbers. Aside from this consideration, this method is usually the better of the two techniques. Users dial 5-digit extension numbers to reach non-local users at DEFINITY ECS or DEFINITY ProLogix Solutions systems, and they dial the same extension numbers as the DEFINITY ECS or DEFINITY ProLogix Solutions users do within their own system. A MERLIN LEGEND Communications System consults the non-local dial plan to route, based on the first four digits, but sends the fifth digit to the DEFINITY ECS or DEFINITY ProLogix Solutions system for handling. “Scenario 5: Large

System Hub” on page 88 provides an example.

For Release 6.0 systems earlier than Version 11, when this method is used, a MERLIN LEGEND Communications System user must dial the fifth digit of a non-local DEFINITY ECS or DEFINITY ProLogix Solutions extension number within two seconds of dialing the fourth digit.

For Release 6.0, Version 11 and later systems, programming the number of dialed digits as 5 makes this restriction unnecessary and speeds call setup time.

■ Program the

last

four digits of the extension number ranges into the nonlocal dial plan, for example 2340–2369 for extensions 12340–12369. Then, when you assign UDP routes to the patterns, program the number of dialled digits as 4 (Release 6.0 Version 11 and later system only), and use the Other Digits system programming setting to prepend the first digit, which in this example is a 1. If it is necessary to route PSTN Direct Inward Dialing (DID) or PRI dial-plan routed calls through a MERLIN LEGEND Communications System to a DEFINITY ECS or ProLogix Solutions system with 5-digit numbering, you must use this method.

NOTE:

It is best to connect DID trunks directly to DEFINITY ECS or DEFINITY ProLogix Solutions systems instead of MERLIN LEGEND Communications System for local routing.

In larger private networks, the second method may cause more numbering conflicts than the first method. You must consider the second digit(s) of DEFINITY ECS or DEFINITY ProLogix Solutions extension numbers to avoid confusion and ambiguity. Extensions 12345 and 2345, for example, are ambiguous when the 1

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must be prepended. Furthermore, users on your system dial only four digits to reach remote extensions while DEFINITY ECS or DEFINITY ProLogix Solutions users dial five digits for intercom calls within their local systems, so extension numbering is not consistent across the private network.

When a private network includes a DEFINITY ECS or DEFINITY ProLogix Solutions system, it is recommended that the MERLIN LEGEND Communications Systems in the private network use 4-digit extension numbers in their local dial plans. One reason is that DEFINITY ECS and DEFINITY Prologix Solutions systems cannot dial anything less than a 4-digit extension number. If a DEFINITY ECS or DEFINITY ProLogix Solutions system is the hub and uses 5-digit extension numbers, calls can be more easily routed through it to reach MERLIN LEGEND Communications System extension numbers that are four digits long. If the MERLIN LEGEND Communications System extension numbers are three digits long, there are more potential numbering conflicts. For example, if a

MERLIN LEGEND Communications System extension number range is 220–249, it can conflict with a very large range of DEFINITY ECS or DEFINITY ProLogix Solutions system extension numbers, 22000–24999. Furthermore, 4-digit numbering provides more room for growth and for easy routing to different types of extensions in a MERLIN LEGEND Communications System, without the need for system renumbering of the local dial plan.

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When planning for centralized VMS/AA, keep in mind that the DEFINITY ECS and DEFINITY ProLogix Solutions systems cannot send coverage or overflow calls to a VMS/AA on a MERLIN LEGEND system, and a MERLIN LEGEND system cannot send coverage or overflow calls to a DEFINITY system’s VMS/AA. The automated attendants on both systems can transfer calls to extensions on the other system. The position of the DEFINITY system within the private network may also affect the ability of MERLIN LEGEND systems to use a centralized VMS/AA. Only a MERLIN LEGEND system directly connected by tandem trunks to the MERLIN LEGEND system where the centralized VMS/AA is installed can send calls to the centralized VMS/AA.

Automatic Route Selection (ARS) 2

Local system users may use ARS to route calls over tandem trunks to the PSTN facilities connected to a remote system.

This arrangement can provide toll cost savings when users need to reach outside

not

numbers that are in a private network. It also means that in some cases, a MERLIN LEGEND Communications System may have only one or two PSTN trunks connected to it for emergency purposes only. Under normal circumstances, the system uses PSTN facilities connected to another system in the private network, which can provide call-volume advantages when buying PSTN services such as domestic long-distance calling. The scenarios later in this chapter provide examples.

in their own local calling area but

are

local to other systems

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The following general rules make ARS routing both simpler and safer:

■ Common Access Code. For proper handling of calls across the private

network, all systems in the private network should use the same ARS access code. Using a common ARS code across the private network provides ease of use for users travelling between sites, and also ensures completion of Dial 0 and 101xxxx equal access code calls.

■ Security.

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—The ARS non-local access code

must not

local dial plan, as mentioned earlier in this section.

—It is the responsibility of the switch where ARS calls originate to prevent

toll fraud.

■ Co-located Network Switches. When two or more systems are located at

the same street address, and one of the systems does not have PSTN trunks connected, some tandem trunks from that system must be assigned to the default pool and all ARS tables (including Table 17, 18, Dial 0, and Special Numbers tables) must prepend the ARS code for the co-located private network system. This will assure that 911 calls will be routed properly and that the correct calling address will be identified.

Additional information about ARS security is included in Chapter 4, “Security.”

Remote Access 2

When non-local users access ARS to dial out over PSTN facilities connected to your local system or to another system connected to yours, your system uses a special form of the Remote Access feature to accommodate these calls. Because calls are routed from one system to one or more other systems, the remote access settings for this purpose are distinct from the Remote Access feature used by individuals who enter a barrier code in order to reach an extension or place an outgoing call on the system.

be programmed into the non-

The remaining topics provide additional details about programming remote access in private networks.

Programming Remote Access over Tandem Trunks 2

Non-local users who access your PSTN trunks via ARS and private network trunks do not dial a remote-access barrier code. For security purposes, the system applies the default class-of-restriction (COR) calling restrictions that you assign to all tie (T1-emulated voice or data, or analog) or non-tie (PRI) trunks, ignoring the barrier code requirement setting. If remote users connect to your system via tandem PRI facilities, the non-tie restrictions apply; otherwise, the tie restrictions apply. You can program both types of COR if needed, using the following system programming procedure (refer to detailed instructions).

System Programming

guide for

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When programming the default COR, change the Calling Restriction option to unrestricted (the factory setting is outward restricted). You should assign Disallowed List 7 to include; 900, 976, and other types of calls that users should not be allowed to call. When a call is received at a non-local system that routes it to another private network system, the FRL assigned to the default COR is compared to the local UDP or ARS route FRL to permit or forbid the routing of the call. For a call to go through, the route FRL must be equal to or less than the default COR FRL. These considerations are discussed in detail in Chapter 4,

“Security.” To make it easier for users working away from their home system in a private

network and for maintenance and toll-saving purposes, you can include non-local systems’ Remote Access codes in your non-local dial plan. Each networked system should have a unique, unambiguous Remote Access code. These numbers must not conflict with extension ranges in the networked systems’ nonlocal dial plans. Calls to the remote access extension that require barrier codes use the COR assigned to the barrier code entered.

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SECURITYlALERT:

Networked systems require special attention to security issues. Follow the rules below when setting up and planning your system for private network use.

■

Ensure that barrier codes are required for incoming remote access calls received on PSTN dial-plan routed and tandem facilities that route to the Remote Access code (889, for example). When you program the default COR, turn the barrier code requirement on. This setting is ignored for ARS calls and calls to non-local extensions across the private network. However, it is still applied to DID and PRI dial-plan routed remote access calls as well as to calls received on a tandem trunk and routed to a Remote Access code. Because the COR Calling Restriction must be set to unrestricted for private network calling, using barrier codes on these facilities is essential in order to apply security measures. When a Remote Access code is

included in the non-local dial plan of the calling system, the caller’s barrier code FRL on the called system is compared to the UDP or ARS route FRL on the called system. See the

Feature Reference

and “Remote Access Default Class-of-Restriction Settings” on page

6 for details.

■

Extension and ARS FRLs should be carefully and stringently assigned in order to prevent unauthorized trunk-to-trunk transfers to local PSTN facilities. Tabl e 4–1, pag e 4-3

explains the operation of

this feature in a networked system.

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Programming Regular Remote Access 2

For explicit remote access use by local system users (or by non-local users for special maintenance purposes, for example), assign PSTN trunks to remote access as you normally would, or use PRI dial-plan routed or DID trunks. Specify

must

that users

enter barrier codes for remote access. Do

trunks as dedicated or shared remote-access facilities.

Tandem Trunks 2

As Chapter 1, “Introduction,” explains, tandem trunks may be either PRI or tie facilities. “Scenario 1: Two Systems, Tandem PRI Facilities” on page 16 the advantages of PRI tandem trunks, which provide enhanced features and performance over tie trunks. Tandem T1-emulated tie trunks provide faster call setup and greater data speeds than analog tie trunks, although they do not provide the full functionality of PRI. Analog tandem tie trunks may be required in some private networks where the systems cannot support additional PRI or T1 facilities and remain within the 80-line capacity of a MERLIN LEGEND Communications System. For examples, see “Scenario 3: Four Systems in a

Series, Mixed Facilities” on page 57 and “Scenario 4: Four Systems in a Star, Mixed Facilities” on page 74.

not

assign tandem

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explains

In Release 6.1 and later systems, when planning for centralized VMS/AA, PRI tandem trunks also provide faster Message Waiting light operation and the ability for the centralized VMS/AA to determine whether calls originated on inside or outside lines.

System managers must assign switch identifiers to designate, for each networked trunk, the type and distance of the system connected to the other end of that trunk. The identifiers serve several purposes: they assure the proper volume levels on private network trunks and allow the proper routing for calls across the private network. For example, if System A is connected to System B by a tandem trunk, on System A that trunk must be programmed with the switch identifier for System B, the system at the other end of the tandem trunk. Similarly, on System B that trunk must be programmed with the switch identifier for System A.

NOTE:

The switch identifier is not programmed on the system that it identifies, but is programmed on the tandem trunks of other systems connected directly to it.

The number range of a switch identifier designates both the type of system connected at the other end of a tandem trunk and the distance between the systems in order to assure proper volume levels for calls (see “Scenario 4: Four

Systems in a Star, Mixed Facilities” on page 74 for an example). The distance is

expressed as

satellite (near)

non-satellite

(far) to designate systems closer than 200 miles or further than 200 miles, respectively.A MERLIN LEGEND Communications System is always identified by a number between 1 and 20 for

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far (over 200 miles) connections and between 21 and 40 for near (under 200 miles) connections. DEFINITY ECS and DEFINITY ProLogix Solutions systems are identified by numbers between 41 and 50 for far connections and between 51 and 60 for near connections.

With a given private network system, all the trunks that connect to another specific system must have the same switch identifier number. For example, if two T1-

emulated tie trunks connect System B to System A, System A’s manager must ensure that both of those tandem tie trunks are labelled with the same switch identifier, which is different from the switch identifier that labels a third trunk connecting System A and System C.

It is strongly recommend that each system have a unique pair of identifiers for far and near. If the switch identifiers are not correctly programmed, routing is disrupted. For example, when the switch identifier of the incoming trunk and the automatically selected outgoing trunk for a call match, another route for the call is selected if possible. However, if all available routes specify systems with matching switch identifiers, the caller hears a fast-busy tone. Otherwise, the call would be routed back to the originating system in a continuous loop. This is called

automatic immediate cycling

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A trunk that is not a tandem trunk has no switch identifier; this is the factory setting for all trunks. This is how the switch distinguishes tandem trunks from central office lines. To remove a switch identifier, see “Switch Identifiers” on page 19

PRI tandem trunks require special programming, much of which is automated for you when a PRI switch type of MERLIN LEGEND-PBX or MERLIN LEGEND-Ntwk is chosen. The switch type for the system

at the other end

of a PRI tandem trunk is selected during system programming. When MERLIN LEGEND Communications Systems are networked, the switch types at each end of a tandem PRI trunk are different. The scenarios provide examples. See “Tandem

PRI Facilities” on page 22 for details.

In Release 6.1 and later systems, the PRI Switch Type Test requests the system at the other end to verify that the correct PRI switch type is programmed. This test should be run only by Lucent Technologies technicians or authorized representatives.

In Release 6.0, outside PRI dial-plan routed and DID calls can be routed to nonlocal extensions. In Release 6.1 and later systems, this capability has been expanded to all types of PSTN trunks by using calling groups with a single nonlocal member. Most of the scenarios in this chapter provide examples.

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Security 2

This topic summarizes security issues that are discussed in more detail in Chapter

4, “Security.” Some security issues have been mentioned in the previous topics, including the

reasons that ARS codes are not included in the non-local dial plan. In addition, keep the following considerations in mind:

■ The ARS access code is permitted only for incoming calls on private

network trunks. It is blocked from incoming PSTN calls.

■ All tandem trunks must be assigned to pools and each pool must contain

the same types of trunks.

■ Users must not be given dial access, Pool button access, or DSS button

access to pools of networked trunks. Instead, they use these facilities via UDP and/or ARS calling. Routing details are included in the scenarios later in this chapter.

■ Despite the trunk-to-trunk transfer restriction, a person using any type of

telephone can transfer the following types of calls:

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—A call on a tandem trunk transferred to a non-local dial plan extension —A call on an outside PSTN facility transferred to a non-local dial plan

extension —A call on a tandem trunk transferred to an outside PSTN line/trunk However, if an extension is prohibited from making trunk-to-trunk transfers,

the user cannot transfer an outside call on a PSTN trunk to another PSTN trunk.

SECURITYlALERT:

An outside call can arrive at an extension on a private network system (System A) and be transferred to an extension on another private network system (System B). The person receiving the transfer on System B can then transfer the call to a local PSTN trunk despite any restrictions that are in effect.

NOTE:

PassageWay® Telephony Services clients cannot perform transfers

across the private network. Instead, the users must transfer calls using a telephone. For an example, see “Scenario 5: Large System

Hub” on page 88.

■ Calling restrictions such as Toll and outward restrictions, Allowed/

Disallowed Lists for extensions, and Night Service restrictions are not applied to UDP calls. Only the extension’s FRL can block completion of UDP calls.

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■ UDP routing applies FRLs to calls over specific routes for pools of tandem

trunks. A different set of FRLs is programmed for ARS routes. However, an

both

extension’s FRL applies to

UDP routes and ARS routes. An extension’s FRL is applied only to local tandem and PSTN calls and is not carried across the private network when the caller uses ARS to direct a call to PSTN facilities on another switch. As you read the scenarios in this chapter, pay attention to the following rules:

—Within a system, ARS FRL restrictions compare the local extension FRL

to the route FRL. To use a route for a call, the extension FRL must be equal to or greater than the route FRL.

—For intersystem calling, the system compares the local extension FRL to

the UDP route FRL. To use a route for a call, the extension FRL must be equal to or greater than the UDP route FRL.

—When a Remote Access code is included in the non-local dial plan of the

calling system, the caller’s barrier code FRL on the called system is compared to the UDP or ARS route FRL on the called system.

—When a UDP or ARS call is routed into a system over tandem trunks and

then out of it again, the FRL assigned to the default COR for all-tie or all non-tie trunks is compared to the FRL assigned to the outgoing UDP or ARS route on the called system. The default COR’s FRL must be greater than or equal to the FRL of the outgoing route on the called system.

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—When a PRI dial-plan routed or DID call is routed across systems in a

private network, the system receiving the call from the PSTN searches the local dial plan and then the non-local dial plan for the destination extension number. If the number is in the non-local dial plan, the call is routed out using the UDP routing pattern for the specified extension

range. For a call to be routed out of the

receiving system, that

system’s COR FRL must be equal to or greater than the UDP route FRL.

—In Release 6.1 and later, when an integrated VMI calling group is used

for routing calls to a centralized VMS/AA, assign an FRL of 0 to the UDP route for the VMI conversion number. The pattern for the VMI conversion number should not be used for any other routing.

SECURITYlALERT:

Networked systems require special attention to security issues. Follow the rules below when setting up and planning your system for private network use.

■

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on a tandem trunk and routed to a Remote Access code. Because the COR Calling Restriction must be set to unrestricted for private network calling, using barrier codes on these facilities is essential in order to apply security measures. When a Remote Access code is

included in the non-local dial plan of the calling system, the caller’s barrier code FRL on the called system is compared to the UDP or ARS route FRL on the called system. See the and “Remote Access Default Class-of-Restriction Settings” on page

6 for details.

■

Extension and ARS FRLs should be carefully and stringently assigned in order to prevent unauthorized trunk-to-trunk transfers to local PSTN facilities. Tabl e 4–1, pag e 4-3 this feature in a networked system.

Chapter 4, “Security,” explains FRLs and how they affect routing in more detail.

Network Configuration Scenarios 2

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Feature Reference

explains the operation of

In this topic, the networking scenarios are distinguished by the types of facilities that connect the systems, geographic locations of the systems, the PSTN facilities connected to each system, the arrangement of the systems in a series or in a star, and the number of systems included in the private network. The following examples are discussed:

NOTE:

Centralized Voice Mail is available for Release 6.1 and later systems only. For Release 6.0 systems, disregard the centralized VMS/AA capability in the following topics. Each system must have its own voice mail application.

■ Scenario 1: Two Systems, Tandem PRI Facilities, page 16. In this

example, two MERLIN LEGEND Communications Systems are linked in a private network using PRI tandem trunks only. This is a

configuration

. The systems are located in different area codes, and each

series

has public-switched network trunks connected to its local system. Each also shares a ce nt r al iz ed V MS /AA lo c at e d at on e o f th e sys t em s. (Release

6.1 or later is required on both systems.) This scenario also illustrates the use of tandem PRI trunks and how they provide greater functionality in private networks than do tandem tie trunks.

■ Scenario 2: Two Systems, Tandem Tie Facilities, page 32. In this

example, two MERLIN LEGEND Communications Systems are linked in a private network using tandem tie trunks only. This is also a series configuration. The systems are located in different area codes, and each has public-switched network trunks connected locally. Each also shares a centralized VMS/AA located at one of the systems. (Release 6.1 or later is required on both systems.) To show how private networks work in a business environment, this scenario provides more details about real-world

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organizational needs and overall feature planning. This scenario also illustrates the way systems work when they are connected by tandem tie trunks only.

■ Scenario 3: Four Systems in a Series, Tandem PRI Facilities, page 57.

In this scenario, there is no hub system. Instead the systems are connected in a linear fashion. Three systems are joined by tandem PRI facilities. A fourth system is connected to one of the others by analog (E&M) tandem tie trunks. One of the systems has its own VMS/AA and the other three share a centralized VMS/AA. The system with the centralized VMS/AA is also called the VMS hub. (Release 6.1 or later is required for all systems sharing the centralized VMS/AA.)

■ Scenario 4: Four Systems in a Star, Mixed Facilities, page 74. In this

scenario, one system acts as the hub and has public-switched network trunks connected to its control unit, as do two other systems connected in a

star configuration

to the hub. The fourt h system has onl y emerg ency PST N trunks connected locally and normal calls are made using PSTN facilities connected to other systems. The systems are linked both by PRI and analog (E&M) tandem tie facilities. All of the systems share a centralized VMS/AA. The system with the centralized VMS/AA is also called the VMS hub. (Release 6.1 or later is required for all systems.)

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■ Scenario 5: Large System Hub, page 88. In this scenario, two MERLIN

LEGEND Communications Systems are linked to a hub DEFINITY ECS or DEFINITY ProLogix Solutions system in a star configuration. Because this star configuration has a DEFINITY ECS or DEFINITY ProLogix Solutions system as the hub, it is not possible to configure a centralized VMS/AA.

NOTE:

DEFINITY ECS and DEFINITY ProLogix Solutions features and operations are beyond the scope of this guide. Scenario 5 discusses the private network from the MERLIN LEGEND Communications Systems perspective.

The scenarios vary according to the types of tandem trunks, applications, outside facilities, and private network configuration (series or star). They compare and contrast the following aspects of private networks, supplying both usage and setup information:

■ Intersystem call-handling to and from extensions on remote networked

systems

■ ARS routing and calling via PSTN trunks connected to a remote networked

system

■ ARS routing and usage when local PSTN trunks are accessed by non-local

users

■ Remote access planning for non-local users calling out on local PSTN

facilities

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■ Remote access planning for private network usage by people who are

calling in either from outside the private network or from an extension that is non-local to their home system

■ PRI dial-plan routed and DID calling across the private network

■ UDP routing for centralized VMS/AA

■ Considerations for PassageWay Telephony Service clients using the

system’s Computer Telephony Integration (CTI) link feature

The scenarios in this section do not show all of the types of equipment, such as fax machines and single-line telephones, that may be included in systems. They only include the types of equipment that are relevant to the examples. You can use the same types of extension equipment in a networked system that you use in a non-networked system.

To better understand your current system, review Scenario 1 if your private

any

network includes

any

includes

tandem tie trunks. Then review the remaining scenario that is most

tandem PRI trunks; review Scenario 2 if your system

like your own. When you are planning private network changes, review one or more of the scenarios that involve system components and facilities for which you are planning. Even though your own private network may not be represented here exactly as it exists, information in a scenario that describes a similar configuration, application, or facilities can be helpful to you.

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If you are planning for a private network using Release 6.0, disregard the information about centralized VMS/AA.

Scenario 1: Two Systems, Tandem PRI Facilities 2

In this scenario, two MERLIN LEGEND Communications Systems are connected in a series configuration via tandem PRI trunks, which provide the best support for features, call-handling displays, centralized VMS/AA, and performance across private networks.

In this private network, the two system managers work closely together and maintain copies of system forms for both systems. If changes must be made, they first discuss them and assess their impact on the private network.

MERLIN LEGEND Communications System Release 6.1

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MOH

VMI Conversion

Number: 7999

—————

Ext. 771

Integrated

VMI Calling Group

ML = MERLIN LEGEND

Communications System

Ext. 3105

Analog Disp

PassageWay

Client/Telephone

PRI

ML A

New Y ork, NY

Area Code 212

Switch ID 21

Home

Volume

Feature

Transfer

Conf

HFAI

Drop

Mute

Speaker Hold

Ext. 3212 MLX-20L

Ext. 3233

MLX-20L

Inspct

Message

ABC DEF

123

MNO

GHI JKL

456

PQRS TUV WXYZ

789

OPER

Ext. 3473

2B Data Video

System

PSTN

Tandem PRI

Facilities

PRI

Holmdel, NJ

Area Code 732

Ext. 6761

Analog Disp

Ext. 6988

PassageWay

Client/Telephone

LS GSGS DID

ML B

Switch ID 22

Ext. 6871 MLX-10D

Ext. 7002

2B Data Video

System

MOH

VMS/AA

Local Members:

Ports for VMS/AA

—————

Ext. 771

Integrated

VMI Calling Group

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Figure 2–1. Scenario 1: Overview

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Tandem PRI trunks provide the following benefits:

■ Faster General Performance. PRI facilities make faster connections

across private networks for ARS calling over tandem trunks as well as faster intersystem call handling.

■ Faster Data Transmission. Networked PRI tandem trunks support digital

data speeds of up to 128 kbps between networked systems for enhanced 2B data videoconferencing and other data applications. Earlier releases permitted a maximum speed of 112 kbps between connected systems.

NOTE:

If you plan to communicate at 64 or 128 (2B data) kbps, use extended superframe (ESF) format with Bipolar 8-Zero Substitution (B8ZS) line coding. Some service providers charge more for this type of T1 circuit. However, it not only allows the higher speed, it is also less susceptible to line errors than other format and coding combinations and can be maintained without taking the facility out of service.

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■ Better Call-Handling Displays. Intersystem calls via networked PRI

facilities can provide the caller’s extension label (for example, caller name), extension number (factory setting), or both name and number at the recipient’s MLX telephone display. Scenario 1 shows the details for different types of telephones.

■ Lower Service Provider Costs. When you use PRI over a private

network, you order a point-to-point T1.5 circuit from your service provider, then program the PRI service yourself rather than leasing it from the service provider. When networked systems are distant, the service provider may need to provide amplification but not PRI switching services.

■ Fractional Use Support. You may place drop-and-insert equipment

between systems connected by a PRI tandem trunk, allowing use of fewer than 23 B-channels. The dropped channels are generally used for dedicated data/video service, and the remaining channels carry voice traffic. The equipment must never drop Channel 24, the D-channel. All channels do count towards the system maximum of 80 lines.

■ Automatic Number Identification (ANI)/Incoming Call Line

Identification (ICLID). If PRI tandem trunks are used, ANI and ICLID information may display at the destination extension.

■ Better Transfer Handling. When a user manually transfers a call across

the private network on tandem PRI trunks and the transfer recipient’s extension is either busy or has turned on Do Not Disturb and has no coverage available, the call returns to the transfer originator. If a call is transferred over tandem tie trunks, or is transferred with automatic completion over tandem PRI trunks, it does not return to the originator when the intended destination is unavailable.

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■ Faster Message Waiting Light Updates. For centralized VMS/AA

systems in Release 6.1 and later, PRI tandem trunks allow Message Waiting light updates to be sent over the signalling D-channel. With tie tandem trunks, Message Waiting light updates compete with other voice and data traffic for available trunks and touch tone receivers. As a result, Message Waiting light updates may be delayed.

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Figure 2–1 on page 2–17

shows some PSTN facilities and PRI tandem trunks in a hypothetical private network that includes two MERLIN LEGEND Communications Systems sharing a centralized VMS/AA. A few extensions are shown so that the scenario can demonstrate how calls are handled and how they display at different types of extension equipment. Sample PSTN facilities are shown to illustrate routing when non-local callers use them or when outside calls are transferred or routed across the private network.

Note the following general facts about this small private network:

■ Both systems share a centralized VMS/AA located on System B. This

might be, for example, a MERLIN LEGEND Mail application.

■ When a caller leaves a message or when a non-local subscriber retrieves

all messages, the centralized VMS/AA sends the Message Waiting light updates over the PRI D-channel. If all available PRI tandem facilities are out of service when Message Waiting light updates are attempted, the updates are queued behind any other earlier queued updates and are retained on the central system until a PRI facility is returned to service. Message waiting light updates cannot be sent through the PSTN.

■ The two systems are located in different area codes in the same large

Mid-Atlantic metropolis. They are not, however, geographically distant or in different time zones. For the purposes of this example, it is assumed that both systems activate Night Service mode at the same time and night service calls are routed to the centralized VMS/AA on System B.

■ ARS can be used to route calls over tandem trunks to another system and

then out to the PSTN trunks connected to that other system. For example, if a user on System A needs to reach an outside party in the 732 (Holmdel, NJ) area code, the call goes over tandem PRI facilities and then to the PSTN through an outside facility connected to System B; if a user on System B needs to reach an outside party in the 212 (New York, NY) area code, the call goes over tandem PRI facilities and then to the PSTN through an outside facility connected to System A. When the preferred routes are used, toll savings are optimal.

■ Coverage for extensions or calling groups on remote systems can be

accomplished by sending overflow or coverage to an integrated VMI calling group consisting of a single non-local extension referred to as the “VMI conversion number.” The call is sent over the PRI tandem trunks to the centralized VMS/AA and includes call information signals that indicate whether the call originated as an inside or outside call. When the caller leaves a voice mail message, the centralized VMS/AA sends the Message Waiting light update over the signalling D-channel to the extension at the remote system.

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Non-Local Dial Plans and Facilities Planning 2

This section shows how non-local dial plans, calling groups, switch identifiers, UDP routing, ARS routing, and remote access are set up for each system. Not all details are provided for all facilities and extensions.

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Table 2–1, page 2-22

shows some applicable extension ranges, patterns, and routes for pools when people in one system call people at non-local extensions. For each route, there is a pool number, an FRL, and assignment of voice and/or data service. Digit manipulation is required for routes that use PSTN trunks, which are assigned high-numbered FRLs and are available to only a few users. Digit manipulation is also required for routing coverage or calling group overflow calls to the centralized VMS/AA. Reserved pools are assigned for high-speed 2B data calls, which must not be queued using the Automatic Callback feature. Restrictive FRLs are unnecessary for these routes, because they are for data only and cannot be used for voice calls.

NOTE:

Pools for voice only calls on PRI tandem trunks should not include data trunks. System Alarms will result if voice extensions try to access data trunks. If PRI tandem trunks carry voice and data calls, “voice/data” should be assigned as the route attribute.

In this example, voice calls over tandem trunks to the non-local system are permitted for all users. When all private network routes are unavailable, voice users can employ Automatic or Selective Callback feature to queue for Route 1. To ensure that high-priority callers are not waiting too long for tandem trunks to become available, split the tandem trunks into separate routes with different FRLs.

The Remote Access code for each system is unique and unambiguous, so that users from one system can make lower cost remote access calls into the other system for technical support reasons or for changing forwarding options at their home extensions on remote systems. Users must enter barrier codes in order to make these remote access calls into the non-local system via the non-local dial plan. Their barrier code FRLs must permit the remote access calls using the UDP routes.

Table 2–2, page 2-24

shows how the system managers set up their local systems so that users on the other system can access their local PSTN facilities. It also illustrates how they allow local users to access PSTN facilities on the other system. Table 2–3, page 2-25

summarizes the key points about routing for calls originating in the private network systems. As you review the tables, note the following rules:

■ Local ARS routing analyzes the initially dialed digits to determine whether a

call can be handled more economically using local or non-local PSTN lines/trunks.

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■ If a call should be routed over a non-local system for toll-saving purposes,

the local ARS routing directs it to a tandem PRI trunk pool, prepending the ARS access code. Local PSTN pools are only used as a fallback option, and more restrictive, higher-numbered FRLs are assigned to these ARS routes. Voice extensions can use the Automatic or Selective Callback feature to queue for the first route when other routes are either busy or unavailable because of FRL restrictions.

NOTE:

Even though the ARS access codes for the two systems match, calls with area codes defined in ARS that are routed via private network trunks still require prepending of the non-local system’s ARS code.

The prepended ARS access code signals the non-local system to handle the call using ARS.

■ Local FRL extension restrictions apply to local ARS calls. Before a call is

routed over tandem trunks, the FRL for that tandem trunk route is checked against the call originator’s extension FRL. The non-local system’s ARS feature subsequently analyzes the call for routing by comparing the FRL for the default COR for non-tie trunks (tandem PRI) with the FRL assigned to the local ARS route. The default COR FRL is set to 3. The route FRL must be equal to or lower than 3 in order for the call to go through.

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■ In Release 6.1 and later systems, when planning for centralized VMS/AA,

an integrated VMI calling group must be created at System A. This integrated VMI calling group is used to route calls to the centralized VMS/AA installed on System B. Refer to “Implementation of Centralized VMS/AA” in Chapter 5 for implementation details.

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Table 2–1. UDP Extension Ranges: Scenario 1

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System A Local Dial Plan: 3100–3299; 3400–3499 Remote Access Code: 889 Integrated VMI Calling Group for Routing to Centralized VMS/AA: 771 Trunks: 3801-3880

Extension Range: 6700–6799, Pattern: 01 Route 01

Pool=3360, tandem PRI trunks FRL=0, Voice

Route 02 Pool=3365, tandem PRI trunks FRL=3, Voice

Extension Range: 6800–6999, Pattern: 02 Route 01

Pool=3364, tandem PRI trunks FRL=0, Both

Route 02, PSTN trunks Pool=3367, FRL=6, Voice No dialed digits are deleted and one plus the area code and exchange are prepended.

Extension Range: 7000–7199 (2B data extensions), Pattern: 03

Route 01 Pool=3366, tandem PRI trunks FRL=1, Data

Route 02 Pool=3362, tandem PRI trunks FRL=3, Data

System B Local Dial Plan: 6700–7199 Remote Access Code: 122 Centralized VMS/AA: 771 Trunks: 8001-8080

Extension Range: 3100–3199, Pattern: 01 Route 01

Pool=4420, tandem PRI trunks FRL=0, Voice

Route 02 Pool=4423, tandem PRI trunks FRL=0, Both

Extension Range: 3200–3299, Pattern: 02 Route 01

Pool=4422, tandem PRI trunks FRL=0, Both

Route 02, PSTN trunks Pool=4424, FRL=6, Voice No dialed digits are deleted and one plus the area code and exchange are prepended.

Extension Range: 3400–3499 (2B data extensions), Pattern: 03

Route 01 Pool=4425, tandem PRI trunks FRL=1, Data

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System A Local Dial Plan: 3100–3299; 3400–3499 Remote Access Code: 889 Integrated VMI Calling Group for Routing to Centralized VMS/AA: 771 Trunks: 3801-3880

Extension Range: 122–122, Pattern: 04 Route 01

Pool=3365, tandem PRI trunks FRL=5, Voice

Route 02 Pool=3360, tandem PRI trunks FRL=6, Voice

Extension Range: 7999–7999 (VMI conversion number for routing to centralized VMS/AA; assigned as single member of integrated VMI calling group 771) Pattern: 05

Route 01 Pool=3360, tandem PRI trunks FRL=0, Voice All dialed digits are absorbed and the digits 771 are prepended.

Route 02 Pool=3365, tandem PRI trunks FRL=0, Voice All dialed digits are absorbed and the digits 771 are prepended.

System B Local Dial Plan: 6700–7199 Remote Access Code: 122 Centralized VMS/AA: 771 Trunks: 8001-8080

Extension Range: 889–889, Pattern: 04 Route 01

Pool=4423, tandem PRI trunks FRL=4, Voice

Route 02 Pool=4420, tandem PRI trunks FRL=6, Voice

Table 2–2. Scenario 1: Facilities Planning, Calls Originating within the private network and Going to the PSTN

Component System A: New York, NY (Area Code: 212) System B: Holmdel, NJ (Area Code: 732)

DS1 Switch Type MERLIN LEGEND-PBX MERLIN LEGEND-Ntwk ARS Access Code 99

Switch Identifiers

22 for a system that is within 200 miles (System B) 21 for a system that is within 200 miles (System A)

Programmed on This System

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Remote Access Code and COR for ARS Calls Routed Via This System

Remote Access code: 889 All non-tie

Outward Unrestricted Barrier Code Required (ignored for UDP extension and non-local ARS calls) Disallowed List 7 FRL=3*

Centralized VMS/AA

Integrated VMI calling group extension: 771 VMI conversion number (non-local dial plan

member): 7999

UDP routing over route 01 or route 02, tandem PRI

trunks FRL=0, voice All dialed digits are absorbed and the digits 771 are prepended.

* Local considerations may require a higher (more restrictive) FRL.

Remote Access code: 122 All non-tie

Outward Unrestricted Barrier Code Required (ignored for UDP extension and non-local ARS calls) Disallowed List 7

FRL=3* Integrated VMI calling group extension: 771 Local dial plan members: extensions for ports used

to connect VMS/AA. Message Waiting light updates for non-local

subscribers are sent over the tandem PRI signalling

D-channel

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Table 2–3. Scenario 1: ARS Routing Summary, Calls Originating within the private network and Going to the PSTN

System A: New York, NY (Area Code: 212) System B: Holmdel, NJ (Area Code: 732)

Dialed or Rec’d Digits Rte Pool Type Abs Prep FRL

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

1 Tandem 0 9 0



1 Tandem 0 9 0

2 Local PSTN 0 0 1 2 Local PSTN 0 0 1





All Local PSTN 4 0 0

1 Tandem 0 9 1





All Local PSTN 4 0 0

1 Tandem 0 9 2

2 Local PSTN 0 0 2 2 Local PSTN 0 0 3



All Local PSTN 0 0 2



All Local PSTN 0 0 1

Rte = Sample route number (1= preferred routes; 2=secondary routes) Prep = Prepended (prefixed) digits Abs = Number of absorbed (deleted) digits FRL= ARS Facility Restriction Level. For calls from the private network tandem

trunks, it is compared to default COR for the type of tandem trunk. For local system calls (including remote access calls) it is compared to the extension or barrier code FRL of the caller.

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Routing for Outside Calls 2

This topic examines routing for hypothetical outside calls, to show how the system managers in Scenario 1 work together to maximize cost benefits from the private network. As you study the call route examples in T able 2–4, page 2-27

general setup as described in Table 2–2, page 2-24 summary in Table 2–3, page 2-25

The first example call shows a user at the System A New York location dialing an ARS call beginning with the digits System B location in Holmdel, NJ. System A’s ARS feature, invoked by the dialed

, allows the call, because the Route 1 (and 2) FRL is 0, equal to the extension

FRL. System A prepends the System B ARS access code, 9, and directs the call to Route 1, tandem PRI trunks connected to System B. The call is accepted by System B, because the FRL for the default COR assigned to all non-tie trunks takes the place of an extension FRL. Its value is 3.

If Route 1 is busy, System A’s ARS directs the call to Route 2, which consists of pools of local PSTN trunks. However, the FRL of 1 for the second route is higher than the extension FRL of 0, so the call is denied. The user hears the fast busy tone and could turn on Selective Callback to wait for an available Route 1 tandem PRI trunk.

, for a call in the same area code as the

Issue 1

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Page 2-26Network Configuration Scenarios

, review the

and the ARS routing

In this example and the others, the local ARS first allows or disallows the call based on the Allowed/Disallowed list and a comparison of the extension FRL and the FRL for the available route. If the extension FRL is equal to or higher than the route FRL, the call is permitted. If the call is routed to the other system, that system’s ARS feature compares its route FRL to the default COR FRL assigned to all non-tie (tandem PRI) trunks before routing the call to the PSTN. Both systems use a default COR FRL of 3. The COR FRL must be equal to or higher than the route FRL in order for the call to go out. In your own system, you may need to assign a lower remote access COR FRL, depending upon whether you want to reserve local ARS routes.

The COR settings also include an option for barrier code requirement. This option is ignored for ARS-routed and intersystem extension calls that arrive on tandem trunks; no barrier code is required for these calls. However, if a remote access DID or PRI dial-plan routed call arrives at the local system from the PSTN, a

barrier code

required; this requirement is important because the default COR settings does not outward restrict such remote access calls. In addition, a barrier code is required when a user dials a Remote Access code that is included in the non-local dial plan. The system managers apply FRL restrictions, outward restrictions, and Disallowed Lists to each barrier code.

Both systems assign Disallowed List 7 to the default, non-tie COR. This list prevents calls across the private network to 900 and 976 numbers, as well as to other numbers that organizations often want to prohibit. See “Facility Restriction

Levels and Remote Access” on page 5 for more information.

Table 2–4. Outside Calls: Scenario 1

Originating or Receiving System Dialed Digits Local Routing Non-Local Routing

System A: Ext. FRL: 0



Route 1: ARS Area Code Table routes to tandem trunk pool, FRL 0, prepends 9

Route 2: ARS Area Code Table routes to local PSTN pool, FR L 1, call pro hibited fo r this user. Call denied.

●

Route 1, System B: Remote acc es s default FRL 3. ARS absorbs 1732, routes to PSTN pool.

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System B: Ext. FRL: 3

System A: Ext. FRL: 1,

Automatic Callback on

System A: Ext. FRL: 1, Automatic Callback on





Route 1: ARS Area Code Table routes to tandem trunk pool, FRL 0, prepends 9.

Route 2: ARS Area Code Table routes to local PSTN pool, FR L 1, ca ll p erm itted for this user.

Route 1: ARS Area Code Table routes to tandem trunk pool, FRL 1, prepends 9.

Route 2: ARS Area Code Table would route to local PSTN pool, FRL 2, call prohibited for this user. Call denied.

All local tandem facilities are busy. Call queues for Route 1. When Route 1 is available:

Route 1: ARS Area Code Table routes to tandem trunk pool, FRL 1, prepends 9.

< = Call sent over tandem trunks | = Call sent over PSTN ● = Call ends

Route 1, System A: Remote acc es s

default FRL 3. ARS absorbs 1212, routes to PSTN pool.

System B: All outside facilities are busy.

Caller hears busy tone. Automatic Callback only work s when local PS TN and private network facilities are busy, not

●

PSTN facilities connected to another system.

System B: Remote access default FRL 3.

ARS absorbs no digits, routes to PSTN pool. |

●

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Continued on next page

Table 2–4. Outside Calls: Scenario 1, Continued

Originating or Receiving System Dialed Digits Local Routing Non-Local Routing

System A: Receives outside dial-plan routed PRI data call at 64 kbps.



System A: PRI dial-plan routing deletes 555, checks local dial plan, then finds number in non-local dial plan. Routes via non-local UDP Pattern 3 to PRI tandem trunk pool 3366 at 64 kbps, Data only

System B: First part of 2B data call arrives at video system, Ext. 7002. When the second call is receive d, the data speed is 128 kbps.

●

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System A: Receives

outside dial-plan routed PRI-ANI voice call.



System A: PRI dial-plan routing deletes 555, checks local dial plan, then finds number in non-local dial plan. Routes via non-local dial plan Pattern 2 to PRI tandem trunk pool 3364, Voice and Data

System A: Receives outside DID call.

System A: Receives outside dial-plan routed PRI voice call and is not available. Integrated VMI calling group provides coverage.





System A: DID receives 6871, checks local dial plan, then finds number in nonlocal dial plan. Routes via UDP Pattern 2 to PRI tandem trunk pool 3364, Voi ce and Data <

System A: PRI dial-plan routing deletes 555, checks local dial plan. Call is sent to integrated VMI calling group 771 (with VMI conversion number 7999). The system finds the group member in the non-local dial plan. Routes via UDP Pattern 05 to PRI tande m trunk poo l 3360. UDP routing absorbs 7999 and prepends

771 (System A’s centralized integrated VMI calling group extension).

< = Call sent over tandem trunks | = Call sent over PSTN ● = Call ends

System B: Arrives at Ext. 6871, MLX-10D

35,75.

System B: V o ic e c all arriv es at Ex t. 68 71, displays as outside call on tandem trunk:

35,75.

System B: Calls ring into centralized VMS/AA and calling information indicates an outside call. When the caller leaves a message, the Message Waiting light update is sent over the private network to extension 3105 on System A.

, displays with ANI information

●



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Intersystem Calling 2

This topic illustrates how different types of calls are made and received in Scenario 1, using the extension numbers and extension equipment types shown in Figure 2–1

they are displayed at different recipients’ extensions within the private network. As you review this information, notice the following features:

■ Because the private tandem trunks are PRI, the systems display calling

■ Wherever a person is in the private network, he or she dials another private

■ Manually transferred calls within the private network display in the same

■ Both outside callers and callers within the private network hear Music On

■ PassageWay client screen displays vary depending upon the PassageWay

■ For centralized VMS/AA, call information signals are sent with the call from

. Table 2–5, page 2-30 enumerates some sample calls, showing how

name, calling extension number, or both for arriving non-local dial plan calls. The display varies according to the display preference programming for the MLX extension. Contrast this display with those in Scenario 2, Table

2–12, page 2-55.

network user the same way regardless of location.

way as direct calls between extensions. The originating extension information is shown, with no indication that the call is a transfer.

Hold when their calls are transferred to a non-local extension.

implementation. Therefore, the table shows the information that the system

can

send to the CTI-linked application; if an MLX-20L®, for example, were

a display telephone receiving the call, the display would appear as shown in the table.

the remote system over the PRI tandem trunk so that the centralized VMS/AA can distinguish between inside and outside calls. Message Waiting light updates are sent over the PRI signalling D-channel from the central site to the remote system so there is no need to compete with voice calls for updates.

Issue 1

August 1998

Page 2-29Network Configuration Scenarios

Table 2–5. Intersystem Calling: Scenario 1

Type of Call Caller Caller Dials Recipient Recipient Sees...

MERLIN LEGEND Communications System Release 6.1

Network Reference

Call-Handling Scenarios

Non-local extension System A: Ext. 3212

Non-local extension System B: Ext. 6988

Non-local extension System A: Ext. 3105

Non-local remote access System A: Extension with

FRL 5

Manual transfer of local inside

System B: Ext. 6988 At extension call from 6871 to non-local extension 3212









6871 Transfer



System B Ext. 6777, MLX-10D Display: Number

System A Ext. 3212, MLX-20L Display: Both

System B Ext. 7019, Analog multiline display

Call routed via Pattern 4 , Route 1, FRL 5. System B accepts call. Remote Access feature requires barrier code

System A Ext. 3212, MLX-20L Display: Both

35,75.

:21*6

35,75.

Not Applicable

5,&.6

Continued on next page

555-661-150

August 1998

Page 2-30Network Configuration Scenarios

Issue 1

Table 2–5. Intersystem Calling: Scenario 1, Continued

Type of Call Caller Caller Dials Recipient Recipient Sees...

MERLIN LEGEND Communications System Release 6.1

Network Reference

Call-Handling Scenarios

Transfer of outside GS/L S call to non-local extension

Transfer of outside PRI-ANI call to non-local extension. Initial System A recipient sees ANI information, for example,

35,75.

Caller ID PSTN call on loopstart line

Transfer of outside call to local extension on System A. Extension is busy or unavailable. Centrali zed VMS/AA provides coverage.

Outside to

System A: Ext. 3105

Outside to

System A: Ext. 3212

Outside to System B,

which routes call to a

local extension that has

delayed Remote Call

Forwarding to a System

A extension turned on.

Outside to System A:

Ext. 3233

Transfer



Transfer





(System B Listed Directory Number)

Transfer



System B Ext. 6871, MLX-10D Display: Number

System B Ext. 6988, PassageWay client, no screen pop from original caller received. Ph one a t extension displays transfer originator information. Display: Both

System B extension user has turned on Remote Call Forwarding to System A Ext. 3212, MLX-20L by dialing:

+

trunk no.) +

(tandem PRI

+

System B Ext. 771, centralized VMS/AA. Call information signals received from System A indicate an outside call.

35,75.

$1*(/2

/'1

Not Applicable

555-661-150

Outside call to calling group on System A. All group members are busy and overflow threshold is reached. Centralized VMS/AA provides coverage.

Outside to System A:

overflows to local

integrated VMI calling

group 771.



(programmed to ring into calling group).

System B Ext. 771, centralized VMS/AA. Call information signals received from System A indicate an outside call.

Not Applicable

August 1998

Page 2-31Network Configur ation Scenarios

Issue 1

MERLIN LEGEND Communications System Release 6.1 Network Reference

Call-Handling Scenarios

555-661-150

Scenario 2: Two Systems, Tandem Tie Facilities 2

Scenario 2 describes a medium-sized, mail-order company that has two locations, one in Chicago and one in California. This scenario includes more system details and fuller descriptions of business needs than do the others in this chapter. The various departments and staff use two MERLIN LEGEND Communications Systems connected by tandem T1-emulated tie trunks that provide fractional point-to-point service; some T1 channels are programmed for voice and others are programmed for data only. In this company, there is one system manager, who

also acts as Manager of Information Systems for the company’s computer systems. It is designed to put networking in the context of a complete system. The company conducts catalog sales with supervised groups of order-takers and customer service representatives. It also sells to large corporate customers through a field sales force.

NOTE:

Issue 1

August 1998

Page 2-32Network Configuration Scenarios

With a view to examining networked systems in a larger context of overall business needs and system features, this scenario discusses the following topics:

■ Company Needs. General, group, and individual requirements for

communications system and application functionality

■ General System Description. A summary of the equipment, features, and

applications that meet company needs overall and specifically help certain work groups and individuals

■ Network Planning and Maintenance. A description of how the private

network is set up and how calls are handled to fulfill the company’s requirements

Company Needs 2

Company needs and the solutions provided by the system fall into the following categories:

■ General. Broad concerns that affect the company as a whole and require

basic decisions about the lines/trunks used in the system

■ Work Groups. Specific communications needs of groups who work

together

■ Individuals. Needs of individuals, such as the system manager and off-site

employees

Figure 2–2

illustrates the locations and staffing.

MERLIN LEGEND Communications System Release 6.1 Network Reference

Call-Handling Scenarios

555-661-150

System C

Headquarters

(Chicago)

VMS Hub

President

Conference

Room with

Conferencing

Operator/

Receptionist

Digital Tie Trunk

Main Entrance

Group Video-

Chief

Financial

Officer

Equipment

Secretaries

Order-Takers (12)

VP Sales/ Marketing

Personnel

Manager

and Customer

Service (6)

VP Product

Design

System

Manager

Issue 1

August 1998

Page 2-33Network Configuration Scenarios

Chief Operating

Officer

Supplies

MIS/

and

Storage

Equipment

Accounting

(8)

Conference

Room

Operator/

Receptionist

Main Entrance

Drafting

(2)

Engineering

(2)

Sales Administration

and Support (5)

Manager

Secretary

Plant

Manager

Shipping/Receiving (2)

Warehouse (6)

Division

Manager

Division Mgr. Sect'y

Plant (12)

Order

Processing

(8)

System D

West Coast

Division

(Palo Alto)

Figure 2–2. Scenario 2: Company Floor Plans

MERLIN LEGEND Communications System Release 6.1 Network Reference

Call-Handling Scenarios

555-661-150

General Needs 2

The company has several broad areas of concern:

■ Connectivity

■ Cost-effective calling

■ Customer service

■ Toll fraud and calling restrictions

In addition, the company would like to provide these features to all or many employees:

■ Easy dialing of non-local extensions and frequently called numbers

■ Covering of calls

■ Answering of calls after hours

■ Share voice/fax messages from customers with co-workers

■ Broadcast voice messages to all employees

Issue 1

August 1998

Page 2-34Network Configuration Scenarios

Connectivity. 2The two sites need to communicate easily by voice and also must

transmit data rapidly back and forth between headquarters and West coast operations.

Many staff members in both locations require connectivity to the company’s customer, inventory, and order processing databases. The company uses two local area networks (LANs) that share data communications equipment (DCE) connected to LAN servers. The LANs are internetworked. Volume is high, and communications must be speedy in order to serve both direct marketing and corporate cust omers.

Customers place orders to high-speed Group IV (G4) fax machines and also use slower analog fax equipment. In addition, some customers transmit orders electronically over the Internet, and off-site employees in particular find Internet electronic mail convenient. They also must access their company voice mailboxes from the field.

Executives and professional staffers use the Internet to communicate with customers and associates outside the company, review developments in their industry, and keep up with professional organizations in their fields.

In addition, executives use videoconferencing to meet without the need for travel. Furthermore, videoconferencing and data-sharing are also essential to ensure that product design and factory operations mesh smoothly and that manufacturing problems are resolved rapidly.

Cost-Effective Calling. 2The company uses incoming and outgoing 800 and

WATS services for customer interaction. In addition, customers need to call in directly when they require help, without going through an operator. They often use an automated response system to check their order status or place a small order.

MERLIN LEGEND Communications System Release 6.1 Network Reference

Call-Handling Scenarios

555-661-150

To simplify cost accounting and make outcalling more economical, field representatives access the West coast system remotely, then use the system to dial out to customers, make intersystem calls to headquarters in Chicago, and make ARS calls to the Midwest.

Employees at each location use ARS to dial numbers in the local calling area of the other system, and the system manager has programmed ARS to decrease toll costs for these calls. Later in this scenario, “Network Planning” on page 44

provides additional details.

Customer Service. 2The company wants customers to receive prompt, courteous

attention when they must speak to an order-taker or customer service representative. The staff works closely together to ensure that agents understand how to use the communications systems effectively to provide the best possible service. The staff supervising the customer service representatives observes the calls to ensure that every customer receives prompt, courteous attention. Managers must ensure that staffing levels and communications facilities respond to customer needs during both peak and off-peak call-in times.

Toll Fraud and Calling Restrictions. 2The company must keep tight control of

telecommunications costs and prevent toll fraud by hackers attempting to access their system remotely and then dial out from it. When a new product is released, the company brings in temporary order-taking agents, and this also presents a toll-fra ud ri sk .

Issue 1

August 1998

Page 2-35Network Configuration Scenarios

Work Group Needs 2

Several groups of people work together and interact with customers and co-workers in similar ways. Some of them also have individual needs.

Table 2–6

outlines the needs of work groups.

MERLIN LEGEND Communications System Release 6.1 Network Reference

Call-Handling Scenarios

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Table 2–6. Work Group Needs

Work Group Nee d s

Issue 1

August 1998

Page 2-36Network Configuration Scenarios

President and vicepresidents, W. Coast Division Mgr., Plant Mgr., Personnel Mgr.

Executive Secretaries

Vice-President of Product Design

Product engineers Quality Assurance

Engineers Plant Manager Drafters

Vice-President of Marketing and Sales

Ability to meet frequently, face to face, without incurring travel costs

Ability to receive bosses’ calls directly, without those calls going through an operator/receptionist

Call-covering by other secretary or centralized VMS/AA Ability to exchange and work together individually on documents and

computer-generated images Ability to meet as a group without incurring travel costs

Ability to access either system remotely for calling customers and associates. Ability to assess performance of order-takers and customer service reps as well as field sales personnel.

Continued on next page

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Table 2–6. Work Group Needs, Continued

Work Group Nee d s

Issue 1

August 1998

Page 2-37Network Configuration Scenarios

Order-Takers and Customer Service Personnel

Ability for small-order customers to access an automatic ordering system in which they use their touch-tone phones to enter account numbers, product codes, and so on, without having to wait for an agent. They have the option of speaking to an agent.

Ability for calls from customers who buy in large quantities to be directed to the groups of agents, bypassing the operator, so that the most-idle agent can answer a call. If no agents are available, the caller should hear an initial announcement stating that an agent will soon take the call and offering the option to leave a voice mail message instead of waiting. For callers who must wait longer, a second announcement is needed to urge callers to stay on the line. While a caller is on hold, he or she should hear music.

Ability to us e a LAN-based software application, in conjunction with PRI-ANI services from a telecommunications provider, to rapidly pop

up database information about a customer, based on the caller’s telephone number.

Hands-free operation of their telephones so they can enter order information, review customer history, or check on orders in progress while talking to a customer

Stringent calling restrictions for all agents except those allowed to use WATS services.

Ability for callers to fax or email orders.

Continued on next page

MERLIN LEGEND Communications System Release 6.1 Network Reference

Call-Handling Scenarios

555-661-150

Table 2–6. Work Group Needs, Continued

Work Group Nee d s

Issue 1

August 1998

Page 2-38Network Configuration Scenarios

Order-Takers’ and Customer Service Supervisor

Ability to observe and control the order agents’ calls (for example, to know who is available) and immediately see whether too many callers are waiting. When a caller has waited a certain length of time or a caller has asked to leave a message, the call should go to a voice messaging system. When a caller hangs up without speaking to a company representative, the supervisor must be able to call the customer back promptly.

Sales Support Staff Barrier code (password) access for remote access callers, to help

avoid toll fraud by hackers

Field Sales Representatives

Factory and Warehouse Personnel

Ability for field representatives to have calls forwarded from the West coast office to their off-site telephones

Ability to be summoned by loudspeaker when necessary Ability to hear an extra alert when a call arrives in some noisier areas Calling restrictions

Individual Needs 2

Table 2–7 describes the individual needs of certain staff members.

Table 2–7. Individual Needs

Staff Members Needs

Executive Managers Ability to make unrestricted calls from any extension

Screening and coverage of all calls, by secretary during normal hours and by centralized VMS/AA after hours

Ability to work or confer without being disturbed, even by secretary

Executive Secretaries Ability to receive bosses’ calls directly, without those calls going

through an operator/receptionist Call-covering by other secretary or centralized VMS/AA when

unavailable

System Mana ger/MIS Manager

Ability to manage two systems using computers Ability to manage one system remotely Ability to generate reports about phone usage, call traffic, and

facilities usage

Continued on next page

MERLIN LEGEND Communications System Release 6.1 Network Reference

Call-Handling Scenarios

555-661-150

Table 2–7. Individual Needs, Continued

Staff Members Needs

Issue 1

August 1998

Page 2-39Network Configuration Scenarios

Operator/ Receptionist (Headquarters)

Ability to page certain groups or all staff members Answering of all calls, except those that go directly to agents or

executive secretaries, by an automated operator who directs calls according to the touch-tones entered by callers; callers can choose to talk to the operator by pressing

General System Description 2

The system includes equipment, system features, and applications to satisfy needs in three categories:

■ Company-wide

■ Work groups

■ Individuals

Company-Wide System Equipment and Features 2

The company uses the following general equipment and applications to provide basic functionality for the business:

■ PSTN Lines/Trunks. Both systems use Digital Signal 1 (DS1) facilities,

connected to the system by 100D modules, providing more features, speed, and toll-fraud security than ground-start or loop-start lines/trunks. The West coast T1 facility consists of 24 channels. A channel functions as a line/trunk and is programmed for voice (analog service) or data (T1 Switched 56 digital service). T1 channels are also used for personal lines, for analog data transfer with outside parties by modem or analog fax machine. T1 Switched 56 digital service supports videoconferencing as well as data exchange through ISDN terminal adapters.



At headquarters in Chicago, order-takers and customer service staffers use outsi de P RI f aci lit ies . T his prov ide s c all rout ing by di al p lan fo r DI D-l ike functionality and allows the phone agents to take advantage of ANI services that the company subscribes to from network service providers. The ANI service provides incoming caller information for customer calls arriving on the customer 800 lines.

At headquarters, the company’s CTI link allows use of PassageWay Telephony Services applications over the company’s LANs, which run

Novell

NetWare® software. MERLIN LEGEND Reporter collects call information from the Station Message Detail Recording (SMDR) jack at the headquarters location.

MERLIN LEGEND Communications System Release 6.1 Network Reference

Call-Handling Scenarios

555-661-150

In addition, each location has one 800 LS/ID line/trunk module. Loudspeaker paging and Music on Hold connect to this module; an emergency loop-start line is also connected to each system for use in the event of a power failure. It also provides needed T ouch-Tone Receivers.

■ Tandem Trunks. The systems are linked by 24 T1-emulated tie channels

programmed for voice and data, and a T1 to the PSTN requiring a 100D module at both sites for private networking, for a total of three 100D modules at headquarters and two at the West coast office.

NOTE:

Later in this scenario, “Network Planning” on page 44 provides

additional information about how private network facilities and calls are set up.

■ Extension Modules. Both systems use 008 MLX extension modules to

connect MLX telephones and digital equipment. One MLX port is used to connect the headquarters’ CTI link hardware, which also links to a LAN server running Novell NetWare software. Each control unit includes 016 tip/ring extension modules for connecting modems, fax/modems, analog fax machines, and automated answering applications.

Issue 1

August 1998

Page 2-40Network Configuration Scenarios

■ Common Equipment. LANs equipped with shared modems and fax

modems serve the data communications needs of many employees at both sites. They also share common-area fax machines, both high-speed digital Group IV and analog devices.

■ General Extension Equipment. Each extension includes an MLX

telephone. Most extensions include a PC or terminal connected to a LAN, sharing digital communications equipment or modems. Some extensions also include ISDN terminal adapters for high-speed data communications.

■ Intuity AUDIX

. The headquarters system has an Intuity AUDIX to supply centralized voice messaging service for both sites. The application connects to a 016 tip/ring extension module.

■ Voice Messaging Service for Both Sites. At the West Coast site, an

integrated VMI calling group with a single non-local member is created with the same main extension number as that of the integrated VMI calling group for the centralized VMS/AA at the Headquarters site. Extensions at the West Coast site with mailboxes on the centralized VMS/AA are assigned to a coverage group. The integrated VMI calling group at the West Coast site is programmed as the Group Coverage receiver for the coverage group and is also programmed to provide overflow coverage for calling groups at the West Coast site.

NOTE:

Since the two systems are connected by tie lines, all calls sent from the West Coast site to headquarters for centralized VMS/AA coverage are treated as outside calls and Message Waiting light updates may be delayed. For better service, use PRI tandem trunks instead of tandem tie trunks.

MERLIN LEGEND Communications System Release 6.1 Network Reference

Call-Handling Scenarios

555-661-150

Other system equipment includes Uninterruptible Power Supplies (UPSs) to supply backup power in the event of a commercial power failure.

People in both locations use these features:

■ Coveri ng Calls . In workgroups and in the executive suite, calls are

covered using SSA buttons, call coverage features (Cover buttons and coverage to the centralized VMS/AA), Call Forwarding, and Group Pickup.

■ Security. Authorization Codes allow executives to call from any extension

using their own privileges. ARS restrictions limit toll-calling privileges for many extensions. The system manager applies most restrictions at the extension level. Temporary calling group agents do not need to make intersystem calls and are prevented from doing so or from making toll calls. For Release 3.1 or later systems, voice mail ports are factory set with an FRL of 0, prohibiting outcalling.

SECURITYlALERT:

For more information about security, consult “Security of Your System: Preventing Toll Fraud,” in Appendix A, “Customer Support Information” and Chapter 4, “Security.”

Issue 1

August 1998

Page 2-41Network Configuration Scenarios

■ Speed Dialing. Personal and System Speed dial codes and directories

help people quickly reach frequently called numbers. Some staff members also use Auto Dial buttons. PassageWay Telephony Services clients use power-dialing applications for rapid outcalling to customers. On each system, the System Directory includes entries for non-local extensions.

SECURITYlALERT:

Never program passwords and/or authorization codes as Speed Dial codes.

Both features and equipment fill paging needs. A loudspeaker paging system connected to the control unit in the West coast office allows the receptionist to

page people working in noisy areas such as the factory. The system’s Group Paging feature serves the same purpose for people in offices.

Work Groups 2

The following work groups use specialized equipment, features, and applications that serve their needs:

■ Executive Managers. Each location includes a conference room with a

group videoconferencing system that allows face-to-face meetings. The systems use one MLX port each (programmed for 2B data). Video extensions use both tandem T1 tie trunks programmed for data to communicate with the extensions on the other system and PSTN digital facilities for meetings with key corporate customers.

MERLIN LEGEND Communications System Release 6.1 Network Reference

Call-Handling Scenarios

555-661-150

■ Agent Groups. When calls are routed by dial plan from outside PRI

facilities with ANI, agents use a LAN-based PassageWay Telephony Services application to access customer information as calls arrive. Calling

party information is used as a key field in the company’s customer database, and allows agents’ PassageWay Telephony Services worktop software applications to bring up customer history files. Customer service representatives use a CTI link power-dialing LAN application to reach large numbers of customers rapidly.

Two delay announcement devices are attached to play messages for customers calling both groups. The primary delay announcement device plays an announcement for callers; a secondary delay announcement reassures those callers who have waited for 30 seconds or more after hearing the first announcement. Callers also hear Music On Hold while they wait. During a delayed announcement, callers have the option of dialing # in order to leave a message for an agent at the centralized VMS/AA, rather than waiting in the calling group queue.

Supervisors have Direct-Line Consoles (DLCs) and Direct Station Selectors (DSSs) with a button for each agent extension on the local system, and with the Extension Status feature to monitor the status of agents’ extensions. The Group Calling Overflow Threshold Time setting signals when too many callers are waiting in the queue. Supervisors use the system’s MERLIN LEGEND Reporter application to respond when a customer calls service or order-taking groups and then hangs up before an agent answers. MERLIN LEGEND Reporter signals a hang-up, recording the phone number of the caller.

Issue 1

August 1998

Page 2-42Network Configuration Scenarios

For Release 6.1 or later systems only, supervisors have Service Observing buttons on their stations so that they may observe calls in-progress at customer service representative’s extensions. Supervisors cannot observe calls across the private network.

For faxed-in orders, fax machines are in a calling group so that they are accessed through one phone number; orders are received by the next available fax machine in the group.

A programmed button on the supervisor’s console signals when too many callers are waiting; its LED signals three levels of severity (Release 5.0 and later systems only) by flashing, winking, or lighting steadily.

All agents’ phones have headsets attached for hands-free operation. Two agents in each group use ISDN terminal adapters to respond to orders

and customer service requests through Internet electronic mail.

■ Engineering Group. Design and quality engineers, along with drafters and

the Vice-President of Product Design, share a desktop videoconferencing workstation in the West coast office. There is also a desktop video system at headquarters. They use this desktop videoconferencing application for data-sharing, video meetings, and cooperative work on documents. Each desktop video system uses one MLX port and two T1 channels (2B data) programmed for data operation; communication is at 112 kilobits per

Lucent Technologies 555-661-150 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

New Features and Enhancements

Page xvRelease 6.1 Enhancements (August 1998)

Private Networking 0

Centralized Voice Messaging 0

Group Calling Enhancements 0

Transfer Redirect 0

Direct Station Selector 0

Call Forwarding 0

SMDR 0

Decrease in Call Set-Up Time 0

PRI Switch Type Test 0

Service Observing 0

Win SPM

Windows NT Driver 0

Prior Releases: Features and Enhancements

Page xixRelease 6.0 Enhancements (February, 1998)

Private Networks 0

Group Calling Enhancements 0

Queue Control 0

Prompt-Based Overflow 0

Centrex Transfer via Remote Call Forwarding 0

IMPORTANT SAFETY INSTRUCTIONS

About This Book

Page xxviiIntended Audience

Page xxviiiHow to Use This Book

Terms and Conventions Used 0

Typographical Conventions 0

Product Safety Labels 0

Page xxxSecurity

Related Documents 0

Page xxxiiHow to Comment on This Book

Introduction

Page 1-2Networking Concepts

Benefits of Networking 1

Network Configurations 1

Lines and Trunks 1

Software Defined Network (SDN) Configu rat ion 1

Considerations 1

Page 1-19Uniform Dial Plan

Page 1-21Centralized Voice Messaging System

Configuration Requirements 1

Tandem Facilities 1

Implementation of Centralized VMS/AA 1

Example 1

Networking Voice Messaging Systems 1

Call-Handling Scenarios

Page 2-2Networking Guidelines

Automatic Route Selection (ARS) 2

Remote Access 2

Programming Regular Remote Access 2

Tandem Trunks 2

Security 2

Page 2-14Network Configuration Scenarios

Non-Local Dial Plans and Facilities Planning 2

Routing for Outside Calls 2

Intersystem Calling 2

Company Needs 2

General Needs 2

Work Group Needs 2

Individual Needs 2

General System Description 2

Company-Wide System Equipment and Features 2

Work Groups 2