Nortel Remote Office 9110, Remote Office 9115, Remote Gateway 9150, RLC Release Note
P0603253 555-8421-102
P0609546 555-8421-102
Remote Office and RLC
1.4.2 Release Notes
Product release 1.4.2 Standard 1.1 December 2003
Copyright © 2003 Nortel Networks. All Rights Reserved.
Printed in the United States of America.
All information contained in this document is subject to change without notice. Nortel
Networks reserves the right to make changes to equipment design or program components
as progress in engineering, manufacturing methods, or other circumstances may warrant.
*Nortel Networks, the Nortel Networks logo, the Globemark, Unified Networks, Meridian 1,
Meridian SL-100, and Succession 1000 are trademarks of Nortel Networks.
MICROSOFT, MS-DOS, WINDOWS, WINDOWS 95, WINDOWS 98, WINDOWS ME,
WINDOWS 2000, and WINDOWS NT are trademarks of Microsoft Corporation.
Standard 1.1
Publication history
December 2003 This is the Standard 1.1 issue of the Remote Office and RLC
Release Notes for Remote Office Product release 1.4.2. This
document provides updated Known problems and Issues corrected
sections.
2 1.4.2 Release Notes for Remote Office and RLC
December 2003
Contents
In this document
About this document 4
What’s new in release 1.4.2? 6
Hardware, software, and documentation requirements 7
Compatibility options 11
Upgrade file names for this release 16
Performing upgrades 17
Important installation notes 19
Impact of delay on voice quality 25
PSTN testing 27
Bridge Ports 31
9150 BRI Configuration property sheet 38
Local Remote Office 9150 unit dialing plan 39
Operation (Remote Office units) 40
Issues Corrected Since 1.4.1 51
Known problems in this release 54
Documentation additions and corrections 61
1.4.2 Release Notes for Remote Office and RLC 3
Standard 1.1
About this document
This document applies to the following firmware and software:
Release 1.4.2 firmware for the Remote Office 9150 units and Reach Line
!
Card (RLC)
Release 1.4.2.1 firmware for the Remote Office 911x series units and
!
Meridian Digital Telephone IP Adapter units
Release 1.4.2 software for Remote Office
!
Release 1.4.0 software for Remote Office Configuration Manager
!
Version 33 firmware for ISDN U-interface and ISDN ST-interface
!
Document purpose
This document describes the features, known problems, and work arounds for
the Remote Office 9150 unit, Remote Office 911x series units, Meridian Digital
Telephone IP Adapter units, and the RLC. It also provides:
information that is not provided in the:
!
— Reach Line Card Installation and Administration Guide
(NTP 555-8421-210)
— Remote Office 9150 Installation and Administration Guide
(NTP 555-8421-215)
— Remote Office 911x Series Installation and Administration Guide
(NTP 555-8421-220)
— Meridian Digital Telephone IP Adapter Installation and Administration
Guide (NTP 555-8421-211)
clarification for items that can prevent the system from operating correctly
!
if they are not configured correctly. Refer to “How to achieve a successful
implementation” on page 5 for more details.
4 1.4.2 Release Notes for Remote Office and RLC
December 2003
Who should read this document
This document is written for individuals who are responsible for the installation,
configuration, and day-to-day management of the Remote Office 9150 unit,
Remote Office 911x series unit, Meridian Digital Telephone IP Adapter unit,
and RLC.
How to achieve a successful implementation
The instructions provided in the Reach Line Card Installation and
Administration Guide (NTP 555-8421-210) and the Remote Office Installation
Testing—Job Aide help you achieve a successful implementation. Specifically,
pay close attention to the instructions for configuring the following:
PBX configuration for ports, DN Discovery, and Caller ID security
!
PSTN numbers used to contact Remote Office units
!
prefix configuration in PSTN numbers on the RLC
!
BRI trunk configuration on the Remote Office 9150 unit
!
Remote Office naming convention
Unless otherwise specified, the term “Remote Office units” refers to the
following products:
Remote Office 9110 unit
!
Remote Office 9115 unit
!
Remote Office 9150 unit
!
Meridian Digital Telephone IP Adapter unit (Internal and External)
!
PBX terminology
Throughout this document, the term “host PBX” refers to any of the following
Nortel Networks PBX platforms:
Meridian 1
!
Meridian SL-100
!
Succession 1000
!
1.4.2 Release Notes for Remote Office and RLC 5
Standard 1.1
What’s new in release 1.4.2?
This is a Remote Office maintenance release. Refer to “Issues Corrected Since
1.4.1” on page 51 for further details.
6 1.4.2 Release Notes for Remote Office and RLC
December 2003
Hardware, software, and documentation
requirements
This section identifies the following items that are required to support this
release:
supported PBX platforms and software releases
!
current hardware, firmware, and software versions
!
documentation requirements
!
Meridian 1 software and platforms
The following Meridian 1 platforms are supported using software release 23 (or
later), or are using the Enterprise Business Package:
Options 11, 11(C) Mini, 11(E), 51(C), 61(C), 71(C), and 81(C)
!
Please note the Option 11 Mini platform restrictions shown in the following
table:
Hardware Restrictions
16-port (single-slot) RLC NTDR68xx supported in slots 1, 2, 3 in the main chassis
and 7, 8, 9, 10 in the expander chassis.
32-port (double-slot) RLC NTDR71xx supported in slot 1 or 2 in the main chassis
(maximum of 1) and 7, 8, or 9 in the
expander chassis (maximum of 2).
Since the 32-port RLC requires two backplane connections, it cannot be
provisioned in slot 10 of an Option 11 cabinet, as this slot has only one
backplane connection.
1.4.2 Release Notes for Remote Office and RLC 7
Standard 1.1
Package requirements
The following four packages are required in the X11 system software for the
proper functioning of Remote Office with all Meridian 1 systems:
package# 0 BASIC (Basic Call Processing)
package# 19 DDSP (Digit Display)
package# 95 CPND (Caller Party Name Display)
package# 170 ARIE (Meridian Modular Sets)
Currently, all four packages are available in the Basic software bundles for all
Meridian 1 systems.
Meridian SL-100 software and platforms
The following Meridian SL-100 platforms (using software release MSL12 or
later) are supported:
SuperNode (with series 70 Processor)
!
SuperNode SE (with series 70 Processor)
!
Note: Meridian SL-100 platforms require a patch to support M39xx digital
telephone sets with Quality of Service (Qos) transitioning. Refer to the Reach
Line Card Installation and Administration Guide (NTP 555-8421-210) for more
information.
Hardware, software, and firmware
The following table identifies the hardware, software, and firmware supported
by the Meridian 1 release.
Current
Nortel
Product
RLC 16-port NA NTDR68AD NTDR68AA 1.4.2
RLC 32-port IPE-NA NTDR70AD NTDR70AA 1.4.2
Product #
Minimum
Nortel
Product #
Current
Firmware
Available
RLC 32-port Opt 11-NA NTDR71AD NTDR71AA 1.4.2
9150-North American NTDR69AD NTDR69AA 1.4.2
9150-CALA and Asia-Pac NTDR92AD NTDR92AA 1.4.2
9150-Australia/New Zealand NTDR92BD NTDR92BA 1.4.2
8 1.4.2 Release Notes for Remote Office and RLC
December 2003
Current
Nortel
Product
RLC 16-port-Euro NTDR68BD NTDR68BA 1.4.2
RLC 32-port IPE-Euro NTDR70BD NTDR70BA 1.4.2
RLC 32-port Opt 11-Euro NTDR71BD NTDR71BA 1.4.2
9150-European NTDR92CD NTDR92AA 1.4.2
9110-Global NTDR76BB 1.4.2
9115-Global NTDR77BB 1.4.2
Meridian Digital Telephone
Internal IP Adapter
Meridian Digital Telephone
External IP Adapter
DSP Module NTDR73AA NTDR73AA N/A
ISDN BRI U-interface module NTDR74AB NTDR74AB 33
ISDN BRI ST-interface module NTDR75AA NTDR75AA 33
Product #
NTDE01BB 1.4.2
NTDE02BB 1.4.2
Minimum
Nortel
Product #
Current
Firmware
Available
Note: With version 1.4.0 of Configuration Manager, you can log on to a unit
with an earlier firmware version to upgrade to the current firmware version.
Remote Office 9150 ISDN BRI Interface information—
for Norway and Sweden only
EN 60950:1992 Annex ZB, Special National conditions, Clause 6.2.1.2 states
that in Norway and Sweden, supplementary insulation for a primary circuit is
required between a Telecommunications Network Voltage (TNV) circuit and
any circuit that has a connection to a protective earthing terminal.
The Remote Office 9150 unit has the ability to support up to four ISDN BRI
circuits. To comply with the specification for supplemental insulation, an
isolation adapter must be placed between each of the Remote Office 9150 unit
BRI inputs and the BRI lines from the service provider.
Isolation adapters are available from local vendors. You can also order the
adapters from Nortel Networks as a merchandise item. The Nortel Networks part
number is P0935714.
1.4.2 Release Notes for Remote Office and RLC 9
Standard 1.1
Documentation
To ensure a successful, trouble-free implementation of the RLC, Remote Office
9150 unit, Remote Office 911x series unit, and Meridian Digital Telephone IP
Adapter unit into your network, have the following items available before you
proceed:
core documentation (confirm that you have the most up-to-date documents
!
by checking the Nortel Networks website, as noted under “Obtaining the
documentation”, below).
— this document
— Reach Line Card Installation and Administration Guide
(NTP 555-8421-210)
— Remote Office 9150 Installation and Administration Guide
(NTP 555-8421-215)
— Remote Office 911x Series Installation and Administration Guide
(NTP 555-8421-220)
— Meridian Digital Telephone IP Adapter Installation and Administration
Guide (NTP 555-8421-211)
— Remote Office Network Engineering Guidelines (NTP 555-8421-103)
— Remote Office Product CD-ROM (NTDR81AG)
The Remote Office Product CD-ROM contains firmware and software as
well as documentation in Portable Document Format (PDF).
supplementary documents and job aids:
!
— Remote Office 911x Series Quick Start Guide
— Meridian Digital Telephone IP Adapter Quick Start Guide
— Installer’s Notes for your hardware component (provided in the box)
— Remote Office and RLC Planning Forms (available on the web)
— Remote Office Installation Testing—Job Aide (available on the web)
Obtaining the documentation
You can obtain the documentation from your Nortel Networks distributor, or on
the Worldwide Web at www.nortelnetworks.com. Click on the Technical
Documentation link and navigate to the Remote Office document(s) that you
are interested in reading or downloading.
10 1.4.2 Release Notes for Remote Office and RLC
December 2003
Compatibility options
This section contains tables that provide compatibility options for Meridian
Digital Telephone IP Adapters, Remote Office 911x series units, and Remote
Office 9150 units. This section also lists the trunk requirements for Remote
Office release 1.3.
M2000 series (M3310, and M3820 European models) and M39xx series
digital telephone set model and accessory compatibility
The following tables show Remote Office and Meridian Digital Telephone IP
Adapter compatibility with M2000 series (M3310 and M3820 European
models) and M39xx digital telephone set models and accessories.
Meridian Digital Telephone IP Adapter and Remote Office 911x
series units
Meridian Digital
Telephone Internal
IP Adapter
Digital Telephone Set Models
M2008D, M2008HFD ✓✓
M2616D ✓✓
M2216D-ACD
M2616CT Cordless Discontinued Discontinued
M3310, M3820 (Europe only) ✓✓
M3902, M3903
M3904 ✓
M3905 (ACD) ✓
M2000 series (M3310 & M3820 European models) Add-on Modules
Headsets ✓✓
External alert ✓✓
Key-based expansion module ✓✓
ATA (Analog Terminal Adapter)
MCA (Meridian Communications
Adapter)
i
Remote Office 9110
and
✓✓
Meridian Digital
Telephone External
IP Adapter
and
Remote Office 9115
✓
i. The host PBX must be running software capable of supporting each digital telephone
set model used.
1.4.2 Release Notes for Remote Office and RLC 11
Standard 1.1
Remote Office 9150 units
Digital Telephone Set Models
i
Remote Office 9150
M2006 ✓
M2008D, M2008HFD
M2616D
M2216D-ACD
✓
✓
✓
M2616CT Cordless Discontinued
M3310, M3820 (Europe only)
M3901
ii
✓
✓
M3902, M3903 ✓
M3904
M3905 (ACD)
✓
✓
M2000 series (M3310 & M3820 European models) Add-on Modules
Headsets ✓
External alert
Key-based expansion module
ATA (Analog Terminal Adapter)
iii
✓
✓
✓
MCA (Meridian Communications Adapter)
✓
i. The host PBX must be running software capable of supporting each digital telephone
set model used.
ii. Refer to “Supported telephone models” on page 63 for required configuration details.
iii. ATA modules support analog telephone sets and facsimile (FAX) machines. ATA
modules do not support modems.
12 1.4.2 Release Notes for Remote Office and RLC
December 2003
M39xx series digital telephone set accessory compatibility
The following table shows Meridian Digital Telephone IP Adapter unit, Remote
Office 911x series unit, and Remote Office 9150 unit compatibility with M39xx
series digital telephone set accessories.
Meridian
M39xx series Digital
Telephone Set Accessories
and Add-on Modules
Headsets ✓✓✓
Digital
Telephone IP
Adapter units
Remote Office
911x series
units
Remote Office
9150 units
External alert & recording
interface
Key-based expansion module
(22-button, up to two per
3904/05)
Display-based expansion
module
ATA (Analog Terminal Adapter)
Personal Directory PC utility
Full-duplex Speakerphone
CTI (Computer Telephony
Integration) Adapter
i. The Remote Office 9150 unit supports ATA modules. These modules support analog
telephone sets and facsimile (FAX) machines. They do not support modems.
i
✓✓✓
✓✓✓
✓✓✓
(Refer to Note i)
✓✓✓
✓✓✓
✓✓✓
1.4.2 Release Notes for Remote Office and RLC 13
Standard 1.1
Communications system and software requirements
The following table shows the software versions necessary to run Remote Office
products on compatible Nortel Networks’ communications systems.
Remote Office 9150, Remote Office 911x series and Meridian Digital
Telephone IP Adapter units
Communications system
Meridian 1 X11 Release 23 or higher
Meridian SL-100 Release 14 or higher
Succession 1000 Release 1.1 or higher
i. Requires Remote Office software version 1.3 or higher.
Supported Codecs
The following tables show the Codecs supported by the Remote Office and
Meridian Digital Telephone IP Adapter units, as well as the data stream, and
approximate peak bandwidth required by each.
Remote Office 9150 units
CODEC Data stream only
G.711 64 Kbps 78 Kbps
i
Approximate total bandwidth, including IP
overhead (30 ms voice packets)
System software version
G.726 32 Kbps 44 Kbps
G.729A 8 Kbps 22 Kbps
Meridian Digital Telephone IP Adapter and Remote Office 911x
series units
CODEC Data stream only
G.711 64 Kbps 78 Kbps
G.729A 8 Kbps 22 Kbps
14 1.4.2 Release Notes for Remote Office and RLC
Approximate peak bandwidth, including IP
overhead (30 ms voice packets)
December 2003
Trunk options for Reach Line Cards
The following is a list of the different trunk options supported by the Reach Line
Card:
VoIP trunk
!
(included through the RLC’s Ethernet interface)
PRI trunk
!
(clear-channel mode)
PRI trunk
!
(56K channel mode)
T1/E1 trunk
!
1.4.2 Release Notes for Remote Office and RLC 15
Standard 1.1
Upgrade file names for this release
Firmware and software files are initially provided on the Remote Office Product
CD-ROM (NTDR81AG). Upgrade files that are downloaded from the Nortel
Networks website are provided in self-extracting executable files.
The following table identifies the upgrade files supported by this document for
the Meridian 1 release.
Notes:
If you are using an Meridian SL-100 PBX, contact your Nortel Networks
!
support representative to determine the Meridian SL-100 upgrade file
names.
To check the current firmware follow the procedure at the bottom of page
!
17.
Component
RLC rlc1_4_2.exe rlc-1_4_2.upg
Remote Office 9150 unit 91501_4_2.exe 9150-1_4_2.upg
Remote Office 911x series units 911x1_4_2_1.exe 911x-1_4_2_1.upg
Meridian Digital Telephone
IP Adapter units
(Internal and External)
ISDN BRI U-interface module isdn33.exe bri33u.upg
ISDN BRI ST-interface module isdn33s.exe bri33s.upg
Configuration Manager cm1_4_0.exe not applicable
Obtaining the latest upgrade files
Nortel Networks
delivery file name Upgrade file name
IPadapter1_4_2_1.exe IPAdapter1_4_2_1.upg
Note: The setup.exe file provided within the
cm1_4_0.exe file is used to perform the
Configuration Manager upgrade.
You can obtain the latest upgrade files from your Nortel Networks distributor, or
on the Worldwide Web at www.nortelnetworks.com. Click on the Support link
and navigate to the file(s) that you are interested in.
16 1.4.2 Release Notes for Remote Office and RLC
December 2003
Performing upgrades
WARNING
To eliminate any confusion in board numbering, the RLC
automatically sets its Unit ID to 254 with this release when
upgrading from releases prior to 1.2.0.
The RLC now identifies the Remote Office units by their Unit
ID, not by their Unit Number or Node Name. If the Unit ID is
not the same as the Unit Number in the Remote Connection
Configuration on the RLC, the Unit ID in the 9150 or 911x
System Configuration sheet must be changed to match the
Unit Number or Node Name.
To maintain compatibility with all installations that support a
single Remote Office unit, the upgrade process assigns the
default Unit ID of “1” to each unit to match the default at the
RLC. Following an upgrade, administrators responsible for
multiple Remote Office units on a single RLC must configure
the correct Unit ID at each Remote Office unit.
For complete details on performing upgrades, refer to the appropriate
Installation and Administration Guide for your specific product.
ATTE NTI ON
The protocol for communication between the RLC and the
Remote Office units requires that they be running the
same version of firmware for them to communicate with
each other.
Nortel Networks recommends that you perform a firmware upgrade if you are
using older versions of firmware (Release 1.3.4.x or earlier). To check the
version of firmware you are using, do one of the following:
If you are not connected to the device, open Configuration Manager and
!
connect to the Remote Office unit. A window displays the RLC or Remote
Office unit firmware version.
If you are already connected to the device, choose System Information
!
➝
System Data. The unit firmware version displays.
1.4.2 Release Notes for Remote Office and RLC 17
Standard 1.1
Each time you perform a firmware upgrade, the configuration database is
converted (if necessary) to a format that is compatible with the new firmware.
The conversion does not affect configuration settings.
To ensure trouble-free communication between the RLC and Remote Office
units during and after the firmware upgrade, Nortel Networks recommends
performing the upgrades as follows:
1 Create backup configuration files for the Remote Office 9150, 911x, and
2 Upgrade the Configuration Manager software on the administration PC.
3 Disable the PBX slot(s) where an RLC is installed.
4 Upgrade the RLC firmware.
Meridian Digital Telephone IP Adapter units and for the RLC. Refer to
“Creating a backup configuration file” in the Installation and Administration
Guide for the specific product.
5 Upgrade the Remote Office 9150, Remote Office 911x series, and Meridian
Digital Telephone IP Adapter unit firmware.
6 Remote Office 9150 units only - Upgrade the BRI module firmware for each
BRI module.
7 Restart the RLC.
8 Restart all units.
9 Re-enable the PBX slot(s).
Note: Upgrade the Remote Office 9150 unit’s firmware before upgrading the
Remote Office 9150 unit’s BRI module firmware.
18 1.4.2 Release Notes for Remote Office and RLC
December 2003
Important installation notes
This section provides important information about the installation of the Remote
Office 9150 unit, Remote Office 911x series unit, Meridian Digital Telephone IP
Adapter unit, and RLC.
Advanced Configuration for upgrades
If you have changed the settings in the Advanced Configuration dialog box
(patch releases only), upgrading to product release 1.4.2 from a product release
prior to 1.4.1 returns the settings in this dialog box, listed below, to their default
values. For these default values, refer to page 64.
NLP
!
Dialtone/DTMF Relay
!
Access the Advanced Configuration dialog box through Configuration
Manager’s RLC System Configuration property sheet to ensure that these fields
contain the proper settings for your system. For more information, refer to
“Advanced Configuration” and “Advanced Configuration settings” on pages 63
and 65, respectively, of these Release Notes. This information also appears in
the Remote Office Configuration Manager Help content for this dialog box.
If you are upgrading to product release 1.4.2 from product release 1.4.1, the NLP
and Dialtone/DTMF Relay settings are not set to their default values but instead
stay the same value as they were configured in product release 1.4.1.
Automatic TEIs (Terminal Endpoint Identifiers)
BRI modules must be used in a point-to-point configuration if using automatic
TEI assignments. They cannot be used in a multi-point configuration. You
should also make sure that no other ISDN devices are on the line.
1.4.2 Release Notes for Remote Office and RLC 19
Standard 1.1
Class of Service RNGI and RNGB
Class of Service RNGI: Class of Service RNGI permits digital telephones to
ring rather than buzz when they are offhook. Local TCM ports on the RLC
support this feature. However, digital telephone sets connected to Remote Office
units do not support DRG2, DRG3 or DRG4. Digital telephone sets connected to
Remote Office units support DRG1, the default ring.
Class of Service RNGB: Class of Service RNGB, like RNGI, applies ringing to
digital telephones that are idle but offhook, but unlike RNGI it also applies
ringing to digital telephones that are busy and offhook on another line.
Note: These features are only available if there are no local calls present on the
digital telephone set. If a local call is present on the digital telephone set, the
ringer is converted to a beep tone (tone B message).
Connecting a telephone set to a port reserved for Bridge Port
invalidates Bridge Port operation
Do not connect a telephone set to the port that is going to be used as a Bridge
Port. This causes the Bridge Port to fail.
DN Discovery port configuration
Nortel Networks recommends that you run DN Discovery on an unused port,
such as a data port, configured with voice capability. For information on
completing this configuration, refer to the Bridge Port configuration section of
the Remote Office 9150 Installation and Administration Guide
(NTP 555-8421-215).
DSP provisioning for faxes
The G729/FAX compression algorithm now provisions two DSP channels for
each G729/FAX transmission. Refer to “DSP allocation” on page 73 of these
Release Notes for details on how to calculate your DSP needs.
20 1.4.2 Release Notes for Remote Office and RLC
December 2003
Flash downloads to M39xx series digital telephone sets
Over an IP network with low delay and packet loss, Flash download times to
remote M39xx digital telephone sets are comparable to PBX wired downloads.
Download times increase when you use PSTN bandwidth on a Remote Office
9150 unit or a Remote Office 911x series unit.
Free-standing key system
Nortel Networks does not support a Remote Office system as a free-standing
key system. If you are searching for free-standing key systems, inquire about the
Norstar and Business Communications Manager product lines.
1.4.2 Release Notes for Remote Office and RLC 21
Standard 1.1
Local DN does not support Multiple Appearance directory number
Re-direction Primes (MARPs) on Remote Office units
Local calling at the Remote Office 9150 unit always results in a call’s being
placed to the first port with the dialed number. Multiple DN appearances are not
supported for local calling on the Remote Office 9150 unit. Therefore, you
cannot configure the same DN to local calling keys on multiple digital telephone
sets connected to one Remote Office 9150 unit.
Refer to “DN Discovery” in the Reach Line Card Installation and
Administration Guide (NTP 555-8421-210) for further details.
Local trunk calls
Local trunk numbers cannot be pre-dialed. You must wait for the local trunk dial
tone before dialing the number.
M39xx call log
When you answer an incoming local call, the digital telephone set records the
calling DN in the call log. However, you cannot dial directly from the Call Log,
as the trunk access code and country code do not always appear. To resolve this,
navigate through the call log to the number that you want to dial. Press the Edit
key and the digit(s) of the missing code(s). Press the Done key. To dial the
revised number, press the Dial key.
For example, the call log for an ISDN number displays the digits 4445551212.
The missing trunk access code (9) and country code (0) are required to dial the
number. Use the Edit key to enter the missing digits, 9 followed by 0. The
number now appears in the M39xx’s LCD display as 904445551212. The
end-user can now press the Dial key to place the call from the call log.
Meridian SL-100 telephone diagnostics fail on 2nd slot
On the Meridian SL-100, the second slot of a double-slot card fails during
diagnostic tests. You should simply ignore the diagnostic test.
22 1.4.2 Release Notes for Remote Office and RLC
December 2003
Multiple Appearance Directory Number (MADN)
Any active Single Call Ringing (SCR)/Single Call No-ringing (SCN) key causes
the Remote Office unit to allocate DSP and WAN bandwidth for that port. This
is necessary to support a privacy over-ride feature available with the SCR/SCN
key. To avoid unnecessary bandwidth from being utilized, it is recommended
that Multiple Call Ringing (MCR)/Multiple Call No-ringing (MCN) keys be
used for MADN appearances at remote sites. Refer to “Dial tone delay,” on page
43 and “MCR keys increase DSP requirements” on this page for additional
information.
MCR keys increase DSP requirements
In determining the DSP requirements of your Remote Office system, your
calculations must consider the number of ports containing MCR keys. The
over-riding concept to keep in mind when determining DSP requirements is that
each ringing or answered telephone call requires one DSP channel.
The following example assumes one 16-port RLC with no additional DSP
Application Modules for an RLC with eight DSP channels. While one telephone
call is active, which uses one DSP channel, a call to an MCR key assigned to
eight Terminal Numbers (TNs) produces a DSP allocation error. The seven
available DSP channels are insufficient for this call. A non-blocking
configuration must include one DSP channel for each simultaneously ringing or
active digital telephone set that you want to support.
Refer to “Dial tone delay,” on page 43 and “Multiple Appearance Directory
Number (MADN)” on this page for additional information.
PBX and Local feature keys
Local Calling keys on digital telephone sets connected to Remote Office units
cannot have features programmed against them on the host PBX.
Power requirement
If you want to connect the Remote Office 9150 unit to an uninterruptible power
supply (UPS), ensure the UPS has a minimum of 100 Watts available.
1.4.2 Release Notes for Remote Office and RLC 23
Standard 1.1
QoS transition recovery
Due to the requirement to support on-demand routers, the IP network is not
continually tested during QoS transition situations. It is tested only when there
are active voice calls over ISDN. As a result, transitioning needs active calls for
the user-configured recovery period in order to switch back to IP.
If you test QoS transition by disconnecting the Ethernet cable from the Remote
Office unit, or RLC, expect up to a 20-second delay before the Remote Office
unit can place or receive a call. You do not encounter this delay when the
network degrades and calls switch to BRI as designed.
Trunk to trunk transfer gives silence
When you transfer a local call using the Trunk Access code to dial an outbound
local call, the corresponding voice path is not established. This function is not
supported.
24 1.4.2 Release Notes for Remote Office and RLC
December 2003
Impact of delay on voice quality
The impact of the different voice algorithms (G.729A, G.726, and G.711) is well
documented. G.729A provides 8 to 1 compression and does not produce perfect
voice quality. Most users consider it quite acceptable, although some users claim
that they can hear the difference between it and G.711. The 8 to 1 compression
ratio and the acceptable voice quality make it the codec of choice for Voice over
IP (VoIP). Multiple instances of transcoding (that is, compressing and
decompressing) can have a significant impact on voice quality. G.729A is more
likely to be negatively affected by transcoding than G.711.
Most users do not understand the impact of network/PSTN delay or the impact
of voice compression algorithms on the perceived quality of voice. In order to
compensate for the variation in transmission time across the network (IP and
PSTN), the Remote Office product uses a jitter buffer to allow voice packets to
pass through it in a constant stream. The purpose of the jitter buffer is to remove
the variable delays from the voice packets sent across the network, thus avoiding
awkward-sounding speech. The default value of this jitter buffer is 90
milliseconds (ms).
Note: Once you configure the jitter buffer, the jitter buffer can vary up to 30 ms
above or below the configured target.
To estimate the total delay the user experiences, add the following values:
jitter buffer delay
!
network delay
!
algorithmic encoding delay of the algorithm in use
!
To make the calculation simple, use 30 ms as the algorithmic delay. (It varies
depending on the voice algorithm, but 30 ms is a good estimate).
1.4.2 Release Notes for Remote Office and RLC 25
Standard 1.1
The following table indicates one-way delay in ms for the common
configurations. It can seem unusual that the ISDN delay is larger than the IP
delay. However, this is due to the serialization delay of sending the packets
across the relatively low-speed (64K) channels provided by ISDN. (The IP
Network delay assumes high-speed Internet access as part of the intranet.)
G729A
IP Network
Delay
Minimum recommended jitter
buffer setting
Algorithmic delay 30 30 30 30
Reasonable network delay 10 20 20 20
Total One Way Delay 70 80 110 140
30 30 60 90
Over
PSTN
G726 Over
PSTN
G711
Over
PSTN
Excessive delay results in users talking over each other (that is, both users
speaking at the same time). Studies vary as to when this becomes a voice quality
problem, but most of them suggest that this occurs between 120 and 180 ms.
Real-time data transmission produces two types of packet loss:
network-related packet loss (that is, packets lost due to either errors or
!
delays in transmission)
jitter buffer-related packet loss (that is, packets lost due to their being
!
thrown away when the jitter buffer is full)
In effect, there is a trade-off between jitter buffer delay (jitter buffer size) and
packet loss delay at the Remote Office unit. The relationship between jitter
buffer size and packet loss has a direct impact on the user’s perception of voice
quality.
Customer feedback and experience indicate that configuring the jitter buffer to
reduce delay produces better results. Delay, as introduced by the size of the jitter
buffer, is inversely proportional to lost packets. A jitter buffer configuration of
30 ms results in less delay, but a greater likelihood of lost (thrown away)
packets. Most customers find packet loss of 1% far more acceptable than an
increase in one-way delay beyond 180 ms.
26 1.4.2 Release Notes for Remote Office and RLC
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