Huawei U-SYS MRS6100 Technical Manual

HUAWEI

U-SYS MRS6100 Media Resource Server
Technical Manual

V100R002

Huawei Technologies Proprietary

U-SYS MRS6100 Media Resource Server

Technical Manual

Manual Version

T2-020261-20051117-C-1.22

Product Version

V100R002

BOM

31026861

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support and service. Please feel free to contact our local office or company
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Copyright © Huawei Technologies Co., Ltd. 2006. All rights reserved.

No part of this document may be reproduced or transmitted in any form or by any
means without prior written consent of Huawei Technologies Co., Ltd.

Trademarks and Permissions

and other Huawei trademarks are trademarks of Huawei Technologies Co.,

Ltd.
All other trademarks and trade names mentioned in this document are the

property of their respective holders.

Notice

The information in this document is subject to change without notice. Every effort
has been made in the preparation of this document to ensure accuracy of the
contents, but all statements, information, and recommendations in this document
do not constitute the warranty of any kind, express or implied.

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About This Manual

Release Notes

This manual applies to the MRS6100 Media Resource Server V100R002 (the
MRS6100 for short).

Organization

The manual is organized as follows:

z Chapter 1 System Overview This chapter introduces the functions and

features of the MRS6100 and its position in NGN.

z Chapter 2 Hardware Structure This chapter introduces the hardware structure,

frames, boards, and typical configuration of the MRS6100.

z Chapter 3 Software Architecture This chapter introduces the overall

architecture, call processing system, and media processing system of the
MRS6100.

z Chapter 4 Media Resource Function This chapter introduces how to collect

and decode the DTMF signal, how the signal tone is generated and sent, how to
send the recorded voice announcement, audio conference, voice codec
algorithm conversion, voice recording, and video announcement.

z Chapter 5 MGCP and SIP This chapter introduces the MGCP and SIP

protocols and their applications with the MRS6100.

z Chapter 6 MRS6100 Terminal System This chapter introduces the

MRS6100 terminal system, the BAM server, operation and maintenance
workstation, emergency workstation, and the communication gateway software.

z Chapter 7 Operation and Maintenance This chapter introduces MRS6100

security management, data storage, data management, alarm management,
traffic statistics, and software patches.

z Chapter 8 Technical Specifications This chapter introduces technical

specifications of the MRS6100, including capacity, processing capability, power
supply and power consumption, and environment requirements.

z Chapter 9 Compliant Standards This chapter introduces the standards

followed by the MRS6100, including standards released by Ministry of
Information Industry of PRC, ITU-T, IEEE, and IETF

z Chapter 10 Reliability Design This chapter introduces the reliability design of

the MRS6100, including hardware design and software design.

z Appendix Acronyms and abbreviations

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Intended Audience

The manual is intended for the following readers:

z NGN planners
z NGN managers
z NGN system engineers

Conventions

The manual uses the following conventions:

I. General conventions

Convention Description

Arial Normal paragraphs are in Arial.

Arial Narrow

Warnings, Cautions, Notes and Tips are in Arial Narrow.

Boldface

Headings are in Boldface.

Courier New

Terminal Display is in Courier New.

II. GUI conventions

Convention Description

Boldface

Button names, menu items, window names, data table and
field names are in Boldface. For example, click OK.

->

Multi-level menus are in bold and separated by forward
slashes. For example, select the File -> Create -> Folder
menu.

III. Keyboard operation

Format Description

Key

Press the key with the key name in Boldface. For example,
Enter, Tab, Backspace, or A.

Key1+Key2

Press the keys concurrently. For example, Ctrl+Alt+A
means the three keys should be pressed at the same time.

Key1, Key2

Press the keys in turn. For example, Alt, A means the two
keys should be pressed in turn.

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IV. Symbols

Eye-catching symbols are also used in the manual to highlight the points worthy of
special attention during the operation. They are defined as follows:

Caution means reader should be extremely careful during the operation.

 Note means a complementary description.

Environmental Protection

This product has been designed to comply with the requirements on environmental
protection. For the proper storage, use and disposal of this product, national laws and
regulations must be observed.

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Table of Contents

Chapter 1 System Overview.........................................................................................................1-1

1.1 System Functions .............................................................................................................. 1-1

1.2 System Networking............................................................................................................ 1-2

1.3 System Features................................................................................................................ 1-4

Chapter 2 Hardware Structure .....................................................................................................2-1

2.1 Logical Structure................................................................................................................ 2-1

2.2 Typical Configuration ......................................................................................................... 2-2

Chapter 3 Software Architecture .................................................................................................3-1

3.1 Overall Architecture ........................................................................................................... 3-1

3.2 Call Processing Subsystem ............................................................................................... 3-2

3.3 Media Processing Subsystem ........................................................................................... 3-3

Chapter 4 Media Resource Function...........................................................................................4-1

4.1 Collecting and Decoding the DTMF Signal........................................................................ 4-1

4.2 Generating and Sending Signal Tones.............................................................................. 4-1

4.3 Sending Recorded Announcements.................................................................................. 4-1

4.4 Audio Conference .............................................................................................................. 4-2

4.5 Converting Voice Codes .................................................................................................... 4-2

4.6 Recording........................................................................................................................... 4-2

4.7 Video Announcement ........................................................................................................ 4-2

Chapter 5 MGCP and SIP..............................................................................................................5-1

5.1 Using MGCP and SIP with the MRS6100 ......................................................................... 5-1

5.2 MGCP ................................................................................................................................ 5-1

5.2.1 Brief Introduction ..................................................................................................... 5-1

5.2.2 Terminologies that You Should Know..................................................................... 5-2

5.2.3 Protocol Stack ......................................................................................................... 5-8

5.2.4 Message Type......................................................................................................... 5-8

5.2.5 Message Structure ................................................................................................ 5-11

5.2.6 Call Flow................................................................................................................ 5-22

5.3 SIP ................................................................................................................................... 5-32

5.3.1 Basic Concepts ..................................................................................................... 5-32

5.3.2 Terms .................................................................................................................... 5-33

5.3.3 Protocol Stack ....................................................................................................... 5-36

5.3.4 Message Type....................................................................................................... 5-37

5.3.5 Message Structure ................................................................................................ 5-40

5.3.6 Call Flow................................................................................................................ 5-54

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Chapter 6 MRS6100 Terminal System.........................................................................................6-1

6.1 System Overview............................................................................................................... 6-1

6.1.1 Structure of MRS6100 Terminal System ................................................................ 6-1

6.1.2 Structure of the Terminal System Software ............................................................6-1

6.2 BAM Server........................................................................................................................ 6-2

6.2.1 BAM Networking...................................................................................................... 6-3

6.2.2 Components of the BAM Software.......................................................................... 6-4

6.2.3 Characteristics of BAM............................................................................................ 6-5

6.3 Operation and Maintenance Workstation ..........................................................................6-8

6.4 Emergency Workstation..................................................................................................... 6-9

6.5 Communication Gateway Software ................................................................................. 6-10

Chapter 7 Operation and Maintenance........................................................................................7-1

7.1 Security Management........................................................................................................ 7-1

7.1.1 Command Group..................................................................................................... 7-1

7.1.2 Workstation Management ....................................................................................... 7-2

7.1.3 User Account Management..................................................................................... 7-2

7.1.4 Login Time............................................................................................................... 7-2

7.2 Data Storage...................................................................................................................... 7-3

7.2.1 BAM Data ................................................................................................................ 7-3

7.2.2 FAM System Data ................................................................................................... 7-3

7.3 Data Operation................................................................................................................... 7-4

7.4 Alarm Management ........................................................................................................... 7-6

7.4.1 Architecture ............................................................................................................. 7-6

7.4.2 Hardware Alarm Reporting Path ............................................................................. 7-7

7.4.3 Software Alarm Reporting Path............................................................................... 7-8

7.4.4 Alarm Levels............................................................................................................ 7-9

7.4.5 Alarm Types ............................................................................................................ 7-9

7.5 Traffic Statistics.................................................................................................................. 7-9

7.5.1 Traffic Statistics Type.............................................................................................. 7-9

7.5.2 Functions and Features of the Traffic Statistics System....................................... 7-10

7.6 Software Patch................................................................................................................. 7-12

7.6.1 Basic Concepts ..................................................................................................... 7-12

7.6.2 Features ................................................................................................................ 7-12

7.6.3 Structure................................................................................................................ 7-13

Chapter 8 Technical Specifications............................................................................................. 8-1

8.1 System Capacity ................................................................................................................ 8-1

8.2 System Processing Capability ........................................................................................... 8-1

8.2.1 Processing Capability.............................................................................................. 8-1

8.2.2 Delay Probability ..................................................................................................... 8-1

8.3 Physical Parameters.......................................................................................................... 8-2

8.4 Reliability Indexes.............................................................................................................. 8-2

8.5 Power Supply and Power Consumption ............................................................................ 8-2

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8.6 Environment Requirements ............................................................................................... 8-4

8.6.1 Storage Environment .............................................................................................. 8-4

8.6.2 Transportation Environment....................................................................................8-6

8.6.3 Operating Environment ........................................................................................... 8-8

Chapter 9 Compliant Standards...................................................................................................9-1

9.1 PRC Standards.................................................................................................................. 9-1

9.2 ITU-T Standards ................................................................................................................ 9-1

9.3 IEEE Standard ................................................................................................................... 9-1

9.4 IETF Standards.................................................................................................................. 9-1

Chapter 10 Reliability Design.................................................................................................. ...10-1

10.1 Security .......................................................................................................................... 10-1

10.1.1 Network Security ................................................................................................. 10-1

10.1.2 System Protection ............................................................................................... 10-1

10.1.3 Data Security....................................................................................................... 10-1

10.1.4 Operation Security .............................................................................................. 10-2

10.2 Reliability........................................................................................................................ 10-2

10.2.1 Hardware Reliability ............................................................................................10-2

10.2.2 Software Reliability.............................................................................................. 10-3

Appendix A Acronyms and Abbreviations ................................................................................A-1

A

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Chapter 1 System Overview

1.1 System Functions

The U-SYS MRS6100 Media Resource Server (the MRS6100 for short) is the core
resource component that provides value-added media services in the NGN. As the
core device, it implements the media resource function in 3G R5. The MRS6100
provides the following functions:

z Announcement
z Digit collecting
z Voice synthesis
z Voice recognition
z Recording
z Faxing
z Audio conference
z Video conference

The Control devices monitor the MRS6100, such as the SoftSwitch and the
application server (AS). In this way, the MRS6100 provides the special resource
functions for the services over the IP network. These functions include:

z Provide the resources
z Communicate with other entities
z Manage and maintain the resources

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1.2 System Networking

Figure 1-1 shows the MRS6100 in the NGN.

Figure 1-1 MRS6100 in the NGN

I. Service management layer

The service management layer provides value-added services and operation support
based on the established calls. It includes the following entities:

z MRS6100

It provides the media processing functions in the basic and enhanced services,
including service announcement, conference, interactive voice response (IVR),
notification, and advanced tone services.

z iOSS

The integrated operation support system (iOSS) includes the network
management system (NMS) and the integrated billing system.

z AS

The application server (AS) is a stand-alone device at the service management
layer. It provides the following functions:

1) Create and manage the logic related to the value-added services and
intelligent network services

2) Provide various open application programming interfaces (API).

3) Provide the development platform for the thirty-party services.

4) Separate service control from call control. This helps introduces new
services.

z Policy Server

It manages the policies for the following aspects:

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1) Access control list (ACL)

2) Bandwidth

3) Traffic

4) Quality of Service (QoS).

z Location Server

It provides the following functions:

1) Mange the routing for the SoftSwitch devices in the NGN dynamically.

2) Indicate the accessibility of call destination.

3) Ensure high efficiency of the call routing table.

4) Reduce the complexity of routing.

z SCP

The Service Control Point (SCP) is the core component of the traditional
intelligent network. it stores the user data and service logic.
It provides the following functions:

1) Start different logic based on the call events reported by the Service

Switching Points (SSP).

2) Query the service database and user database based on the service logic.

z Send call control instructions to the related SSP to control its next action.
z Implement the intelligent calls.

II. Network control layer

The network control layer implements call control. It uses softswitch as core
technology to implement basic real-time call control and connection control.

As shown in

Figure 1-1, the SoftX3000 SoftSwitch is the core device in the NGN. It

implements the following functions:

1) Call control

2) Media gateway access control

3) Resource allocation

4) Protocol processing

5) Routing

6) Authentication

7) Charging

8) Provides basic voice services, mobile services, multimedia services, and APIs.

III. Core switching layer

The core switching layer adopts the packet technology. It is composed of the devices
like routers and layer-3 switches in the backbone network and the metropolitan area
network (MAN). It provides subscribers with a unified and integrated transmission
platform with high reliability, quality of service (QoS) assurance and a large capacity.

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IV. Edge access layer

The edge access layer connects the subscribers and terminals with the network by
various access means. It converts the original information formats into those that can
be transferred over the network. The following devices can connect with the network:

z Integrated access device

The integrated access device (IAD) is a user access layer device in the NGN. It is
used to introduce the data, audio, and video services to the packet based
network.

z Access media gateway

The access media gateway (AMG) provides multi-service access, including
analog user access, integrated services digital network (ISDN), V5, and x digital
subscriber line (xDSL).

z SIP phone

The SIP phone is a kind of multimedia terminal device that supports the Session
initiation protocol (SIP).

z H.323 phone

The H.323 phone is a multimedia terminal device that supports the H.323
protocol.

z SG

The Signaling gateway (SG) connects the No.7 signaling network with the IP
network. It converts the N0.7 signaling of the public switched telephone network
(PSTN) and the signaling of the IP network.

z TMG

The Trunk media gateway (TMG) is located between the circuit switched network
and the IP packet switched network. It converts the formats between pulse code
modulation (PCM) signal streams and the IP media streams.

z UMG

The Universal media gateway (UMG) converts the media stream formats and the
signaling. It can act as a TMG, a built-in SG or an AMG. It can connect the
devices such as PSTN exchange, private branch exchange (PBX), access
network, network access server (NAS), and base station controller.

1.3 System Features

The MRS6100 provide the following features:

I. Open protocols and standard NMS interfaces

The MRS6100 supports open protocols like the SIP and the media gateway control
protocol (MGCP). It provides various interfaces to connect with the entities, such as
softswitch devices, AS, media gateways, IP intelligent terminals, and NM center. With
these interfaces, the MRS6100 can meet your special networking requirements.

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z Open protocols

The MRS supports the following open protocols:

1) MGCP

2) SIP

3) Real-time transport protocol/RTP control protocol (RTP/RTCP)

4) Session description protocol (SDP)

5) Voice extensible markup language (VoiceXML or VXML) protocol, HTTP,
FTP, NFS and TCP/IP.

z The standard NMS interface is the man-machine language (MML) interface.

II. Large capacity and high integrity

z The MRS6100 supports up to 7200 voice channels to ensure smooth expansion.
z The MRS6100 supports up to 5,184,000 Busy Hour Call Attempts (BHCA).
z The MRS6100 uses standard frame, which is 9 U high, and 19 inches wide. This

ensures high integrity of the system.

III. High reliability design

The MRS6100 has the following reliability features:

z Supports redundancy design on the hardware and software.

For example, the MCCU and the SMUI use the “1+1” backup mode to ensure
high reliability of the devices.

z Provides auto-detection for faults and self-healing capability.

The MRS6100 can detect its hardware and software for faults automatically. if the
hardware or software is faulty, the MRS6100 reports alarms automatically. The
system then switches from the primary server to the secondary server to remove
the fault. If the fault cannot be removed, the system resets automatically for
recovery.

z Provide perfect protection functions against exceptions, including:

1) System power cut protection

2) System power switch protection against misoperation

3) Lightning protection for system power supply,

4) Overvoltage and undervoltage protection

5) Short circuit protection,

6) Overcurrent and overvoltage protection for power supply and interfaces

7) Internal temperature regulation and protection for power supply.

8) The system is protected when it receives any exceptional packet.

z Ensure data security

You can back up the system-class critical data to your hard disk or CDs,
including:

1) Device running parameters that you configure

2) Statistical information

3) Operator information

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4) Administrator information

5) Logs.

z Ensure operation security

The MRS6100 ensure the system security on the following aspects:

1) Operator management

2) Login and logout control

3) Security control and protection

4) Operation logs.

5) Authority management

The MRS6100 authenticates the user before login and records the detailed operation
logs to ensure the system security and traceability.

IV. Handy and practical O&M functions

The MRS6100 provides the following handy and practical operation and maintenance
(O&M) functions:

z Flexible and diversified management modes

The MRS6100 provides you with multiple maintenance modes such as the
graphic user interface (GUI) client and MML You can set up your NMS network
flexibly based on the network structure, management requirements and
investment scale. The MRS6100 support multi-access to the system from local
or remote clients.

z GUI

The OMS uses the O&M interface with the navigation tree. The MML Client
works with the GUI to ease your O&M tasks.

z Powerful traffic statistics capability

The MRS6100 uses lists a graphics to analyze and display the performance data.
It monitors the real-time performance data and collects the background
performance data. The MRS6100 also can meet your customized traffic statistics
requirements.

z Real-time fault management

The MRS6100 receives and reports the faults about the network devices in real
time. It provides real-time audible and visible alarms through the topology, alarm
panel, or the alarm box. Also, the MRS6100 provides the fault management
system to report and filter leveled faults. This helps the carriers quickly locate
and remove the faults.

z Comprehensive help system

The online help is integrated in the MRS6100. You can retrieve the help system
whenever you want.

z Other functions

The MRS6100 also supports the following functions:

1) Install software patches online.

2) Debug the system online.

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3) Maintain the system remotely.

4) Set the data dynamically.

5) Trace signaling and interfaces

6) Interpret the messages.

V. Smooth expansion

The MRS6100 features smooth expansion.

The hardware uses the modular structure. You can add new boards whenever you
want to expand the system capacity.

VI. Convenient update

z Easy to update

The MRS6100 setup interface features Windows style. It provides the similar
setup wizard. The default settings are most applicable. This helps you install,
upgrade or recover the system easily. The program design is separated from the
data design. This ensures that the updated system can inherit the legacy data.

z Safe to update

During the update, the MRS6100 setup program backs up the system database
in multiple modes several times to ensure system security. Also, the MRS6100
setup program backs up the loading files of the old version to ensure that the
system files can be restored to the old version if the new version fails to be
loaded.

z Online update

The MRS6100 provides uninterrupted online update for network services

z Separate update tool

The MRS6100 provides you with a separate tool to ensure update efficiency and
security.

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Chapter 2 Hardware Structure

2.1 Logical Structure

Logically, the MRS6100 hardware consists of the following subsystems:

z System support subsystem
z Call processing subsystem
z Media processing subsystem
z External O&M terminal

Figure 2-1 shows the logical hardware structure of the MRS6100.

Figure 2-1 MRS6100 hardware logical structure

Table 2-1 lists the buses for the MRS6100.

Table 2-1 MRS6100 buses

Bus Index Description

Shared resource
bus

4.8 Gbps

The bus is used for loading, data backup,
and system maintenance.

Switched fast
Ethernet (FE)
bus

Double-star
shaped, 100
Mbps

The signaling processing units and service
processing units use the Ethernet as
inter-board service communication channels
to ensure smooth service processing flow.

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I. System support subsystem

This subsystem loads the software or data, manages and maintains the devices, and
implements the inter-board communication.

It includes the System Management Unit (SMUI), the System Interface Unit (SIUI) of
the SMUI, and the Hot-Swap and Control Unit (HSCI).

z SMUI

The SMUI is the main control board of the frame. It loads the devices, configures the
data, and controls their working status.

z HSCI

The HSCI implements the bridging between the left and right shared resource buses,
board hot swap control, and intra-frame Ethernet bus switching.

The HSCI does not include a CPU. It is configured and maintained through the shared
resource bus by the SMUI.

II. Call processing subsystem

This subsystem provides the call processing function for the SIP and the MGCP.

The Media Call Control Unit (MCCU) resolves the SIP and the MGCP. The VPS
interprets the VXML script. The MCCU and the VPS communicates with the Media
Service Unit (MSU) through the internal Ethernet bus to control the MSU for media
processing.

III. Media processing subsystem

This subsystem processes the media streams, including

z RTP/RTCP
z Voice codec
z Conference bridge
z faxes

IV. O&M subsystem

This subsystem manages and maintains the entire system. It consists of the following
devices:

z Back Administration Module (BAM)
z Work Station (WS)
z Emergency WS

2.2 Typical Configuration

Figure 2-2 and Figure 2-3 shows the configuration of the MRS6100. The SMUI, SIUI,
HSCI, ALUI, MCCU, and the UPWR must be installed and fastened in the fixed slots.

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Each MSU can support up to 400 uncoded announcement voice channels or 240
codec IVR voice channels. You can configure the MSU as required.

I. Configuration without the VXML resolution unit

Figure 2-2 MRS6100 configuration without the VXML

II. Configuraiton with the VXML resolution unit

Figure 2-3 MRS6100 configuration with the VXML

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Chapter 3 Software Architecture

3.1 Overall Architecture

The MRS6100 uses the hierarchical modular software architecture from the top down.
The design focuses on integration. This ensures that the system is highly reliable,
easy to maintain, and easy to expand. The MRS6100 is also a distributed software
system. It runs on the MCCU, MSU and the VPS.

Logically, the MRS6100 software system consists of three modules:

z Call processing subsystem
z Media processing subsystem
z System support subsystem

Figure 3-1 shows the software architecture of the MRS6100.

Figure 3-1 MRS6100 software architecture

I. System support subsystem

This subsystem is the software platform of the MRS6100. It uses HUAWEI distributed
object-oriented programmable real-time architecture (DOPRA) platform middleware
to provide the application layer with the uniform APIs.

Also, the support subsystem provides the upper layer with the implementation
mechanisms on the following functions:

z O&M
z Alarm management
z Traffic statistics
z Signaling and user tracing
z Data backup
z Board switchover
z Online loading

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II. Call processing subsystem

This subsystem interprets the MGCP, SIP, and the VXML scripts.

III. Media processing subsystem

This subsystem processes the media streams, including:

z Dual tone multi-frequency (DTMF) detection
z Audio record and announcement media streams
z Transcoding

3.2 Call Processing Subsystem

The MCCU board is responsible for call processing, including

z Lower layer interface processing
z Transport layer protocol processing
z Call control protocol processing.

Figure 3-2 shows the software structure of the call processing subsystem.

Figure 3-2 Software structure

II. Lower layer interface processing

The Ethernet IP interface is the lower layer interface protocol of the call processing
subsystem. The MCCU board processes the media access control (MAC) protocol
and the IP packets.

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III. Transport layer processing

The call processing subsystem processes the transport layer protocols like the UDP
and the TCP. These protocols bear the call control protocols like HTTP at the upper
layer over the IP network.

IV. Call control protocol processing

The MRS6100 supports the following call control protocols:

z MGCP

The MRS6100 processes the MGCP as follows:

1) Receive the call requests from the SoftSwitches.

2) Connect with the MGCP and the IAD or the AMG terminals.

3) Provide the announcement digit collecting or recording services for the terminals
based on the call requests sent by the SoftSwitches.

z SIP

1) Receive the call requests from the AS.

2) Connect with the SIP terminal.

z Provide the announcement digit collecting or recording services for the SIP

terminal based on the call requests sent by the AS.

z VXML

The MRS6100 process the VXML protocol as follows:

1) Receive the call requests from the AS.

2) Connect with the terminal.

3) Provide the announcement digit collecting or recording services for the terminals
based on the call requests sent by the AS.

3.3 Media Processing Subsystem

This subsystem performs the following tasks:

z Manage the media resources of the MRS6100.
z Control and process the service flows.
z RTP media stream transcoding.
z Provide the media processing resources for the external SoftSwitches or AS.

Figure 3-3 shows the software structure of the media processing subsystem.

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Figure 3-3 Software structure of the media processing subsystem

I. Media resource management

The MRS6100 allocates and manages its resource through the media resource
management module. This module provides the following functions:

z Allocate the channel and conference resources to each SIP/MGCP call
z Reserve the resources.
z Recover the resources when the connection is released.

II. Service flow control

The MRS6100 serves as a media resource pool. It provides media services to the AS
or SoftSwitches. The MRS6100 also controls the service flows to simplify the
operation and control on the AS and SoftSwitches.

III. Media processing

Media processing includes:

z Transcoding
z Announcement
z Digit collecting
z Mixing
z Recording.

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Chapter 4 Media Resource Function

4.1 Collecting and Decoding the DTMF Signal

The MRS6100 can monitor the DTMF signal in the RTP voice payload or the RTP
payload in RFC2833 format.

The MRS6100 receives the DTMF signal from the DTMF phone under the control of
the AS or SoftSwitches. It recognizes the dialed number. Then, the MRS6100
converts the number into the related digits and encapsulates it in the signaling to
transfer it to the AS or SoftSwitch.

Based on the digit map delivered by the service logic, the MRS6100 receives the input
information. If the input digit sequence matches a digit template in the digit collecting
templates, the MRS6100 reports an event and the input data to the service logic. If the
digit sequence does not match any digit template in the digit map, this digit sequence
is invalid.

Also, the MRS6100 can receive the input information based on the special functional
keys delivered by the service logic. According to the definitions of the keys, the
MRS6100 interacts with the user.

4.2 Generating and Sending Signal Tones

The MRS6100 can recognize signal tone identifiers from the SoftSwitches or AS.
Then, it generates the related signal tones, such as dial tone or busy tone to the user.
These signal tones comply with the YDN 065-1997 specifications.

4.3 Sending Recorded Announcements

The MRS6100 plays the recorded announcements to the user in a specified voice
code format based on the requirements of the control device. The announcement
code can be G.711 A/u, G.729A, or G.723.1. The recorded announcements can be
loaded onto the boards of the MRS6100 or stored on the FTP server. Each MSU
board of the MRS6100 can load 200 MB audio files. The audio files on the server are
limited only by the space of the server.

In addition, the MRS6100 can play variable voices in a specified format. The voice
format and value are specified by the service logic.

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4.4 Audio Conference

Under the control of control devices, the MRS6100 provides the multiparty conference
function. It supports multi-coded terminals at the same time. The organizer can
control the conference in real time.

The MRS6100 supports IP based audio conference. The MRS6100 audio conference
function has the following features:

z Support up to 120 parties in a conference.
z Support up to 2,400 three-party conferences.
z Provide the recording and announcement functions for the conference.
z Provide the recording, announcement, and digit collecting functions for a party in

the conference.

z Provide the enhanced control function over the conference.

4.5 Converting Voice Codes

The MRS6100 supports various voice codec algorithms such as G.711A/u, G.723.1,
G.726, and G.729A. It can convert the codec algorithms as required.

4.6 Recording

The MRS6100 supports recording for a channel or for the conference. It supports
several audio file formats, such as G.711A/u and G.729A. The recorded audio files are
stored in the specified directory on the FTP server.

4.7 Video Announcement

Under the control of the SoftSwitches or AS, the MRS6100 provides the video
announcement function. This function has the following features:

z Support multiple video codes, such as H.263.
z Support multiple image formats, such as CIFand QCIF.
z Support multiple video rates ranging from 64 kbps to 384Kbps.

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Chapter 5 MGCP and SIP

5.1 Using MGCP and SIP with the MRS6100

Figure 5-1 Using the MGCP and SIP with the MRS6100

As shown in

Figure 5-1, the MRS6100 can be controlled by the SoftSwitch or the AS.

The control protocols include the MGCP, SIP, and the H.248.

z Under the control of the SoftSwitch, the protocols are used in the services

provided by the SoftSwitch, such as basic call services and supplementary
services.

z Under the control of the AS, the protocols are used in the services provided by

the AS, such as conferences, voice e-mail, and uniform communications.

5.2 MGCP

5.2.1 Brief Introduction

RFC2705 defines the API and the related MGCP. The MGCP is used to control the
voice over IP (VoIP) gateways from external call control units.

The MGCP defines a call control structure. In this structure, call control is separated
from the service bearer. As shown in

Figure 5-2, the call control function is separated
from the media gateways (MG). The function is implemented by the external call
control unit, such as the media gateway controller (MGC) or the call agent (CA). The
MG executes the commands sent from the MGC. Therefore, the MGCP is essentially
a master/slave protocol.

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Figure 5-2 MGCP

5.2.2 Terminologies that You Should Know

I. Gateway

The gateway is a network element that implements interconnection and interworking
between networks with different architectures. In the NGN, the NGN interconnects
with other networks through the gateways likes TMG, AMG, or UMG.

II. Call agent

The call agent (CA) provides signaling and call processing functions. It is an external
call control element used to control the telephony gateways.

III. Endpoint

The endpoint is the data source or data sink. It can be a physical link or a virtual link
running on the physical link.

For example, the interface through which the trunk gateway terminal connects with
the PSTN exchange and the E-phone interface that the access gateway connects are
physical endpoints. The audio source in the MRS is a virtual endpoint.

To create a physical endpoint, you need to install the related hardware. To create a
virtual endpoint, you do not need to do so. You can use the related software to create
a virtual endpoint.

IV. Endpoint identifier

Endpoints are identified by endpoint identifiers. Endpoint identifiers are not case
insensitive.

An endpoint identifier consists of two parts:

z The local name of the endpoint in the gateway, and
z The domain name of the gateway.

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The two parts are separated by @, for example, ms/cnf/1@ mrs6100.huawei.com.
The syntax of the local name depends on the type of the endpoint. The local name
can be leveled to forma naming path from the gateway name to other endpoints.

An endpoint identifier must comply with the following conversions:

z Each identification item in the naming path must be separated by a slash (/).
z Each identification item must be letters, numbers or other printable characters.

The item cannot include delimiters like /, @, or space.

z Wildcards like * or $ can be used in local names. * represents all the endpoints

above this level; $ represents one endpoint above this level.

In the MGCP, the gateway is identified by the domain name, for example,
mrs6100.huawei.com. The local name can consist of a physical interface name, for
example ms/cnf, and a terminal identifier, for example, the port number or identifier
that corresponds to the telephone number accessing the media gateway). The
terminal identifier is separated from the physical interface name by /.

For example, suppose that the AMG endpoint is ms/cnf/[e-mail].

It represents the first endpoint of the ms/cnf interface of the MRS media gateway. The
domian name of the gateway is mrs6100.huawei.com.

For example, suppose that the endpoint name of the TMG is
X35V3+A4/[e-mail].

It represents the thirteenth time division multiplexing (TDM) circuit on the X35V3+A4
interface of the 23# gateway in the example network.

V. Calls and connections

Connections may be either point to point (P2P) connections or multipoint connections.
A P2P connection is an association between two endpoints that send data to each
other. Once the association is set up on both sides, the data is transferred between
them. A multipoint connection is an association among multiple endpoints.
Connections can be set up over different bearer networks.

Connections are managed at endpoints and can be converged into calls.

Connections are grouped by call. One call can include one or more connections. The
setup of connections and calls are initiated by of one or more MGCs.

Figure 5-3 shows the relations among endpoints, connections, calls, and gateways.

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Figure 5-3 Relations among endpoints, connections, calls, and gateways

When the two gateways are managed by the same CA, the connection can be set up
through the following steps:

1) The CA asks the first gateway to create a connection on the first endpoint. The

gateway allocates resources to that connection and responds to the command
through a session description. The session description contains the information
necessary for a third party to send the packets to the connection, such as IP
address, UDP port, and packing parameters.

2) The CA then asks the second gateway to create a connection on the second

endpoint. The command carries the session description provided by the first
gateway. The gateway allocates resources to this connection and responds to
the command through a session description.

3) The CA provides the second session description to the first endpoint by using the

command for modifying connections. Once this process is complete, the two
endpoints can communicate with each other.

VI. Connection identifier

The gateway creates the connection. It assigns a unique identifier for the connection
on the local end. The connection identifier is a hexadecimal character string.

VII. Call identifier

Calls are identified by unique identifiers. The identifiers are created by the MGC. Call
identifiers can be considered as unstructured character strings. When an MGC builds
several connections for the same call, the connections must be associated with the
same call.

VIII. Naming CA and other entities

In the MGCP, the CAs are identified by domain names. To enhance the system
reliability, the MGCP can have a redundant CA. These CAs share the same domain

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name but have different network addresses, such as IP addresses. Typically, the
gateway identifies a CA through its domain name. For lower-layer operations, the
gateway obtains the CA network addresses list from the domain name server (DNS),
and then uses an appropriate network address to communicate with the CA. The
redundancy mechanism is very helpful to enhance the reliability of the MRS6100.

Other entities, such as gateways and information servers, are also identified by their
domain names. Also, these entities can use the redundancy design to enhance the
reliability of the system. The CAs and gateways identify these entities through their
domain names.

With the domain names, you do not need to identify these entities using their network
addresses. The domain names are relatively stable while the network addresses can
be easily changed. For example, if an entity is moved to a different local access
network (LAN), the IP address of the entity will be changed. But you can keep using
the same domain name. The domain name lifetime ensures that other entities can
obtain the new IP addresses by updating the domain name information.

In the MGCP, CAs and other entities are represented by e-mail addresses.

For example:

[e-mail] represents the CA in the example network

[e-mail] represents the busy signal in the 12# information
server in the example network

IX. Events, signals, and packages

Events and signals are essential to the MGCP. The CA may ask to be notified about
certain events that occur at an endpoint, such as offhook, onhook, flash-hook, or
dialing. The CA may request certain signals to be applied to an endpoint, such as dial
tone, ring back tone, or busy tone.

Events and signals are integrated into packages. Each package is supported by a
specific endpoint.

An event is named in the following format:

Package name/event name

In the name, the package name is optional because each type of endpoint has a
related default package. If the package name is not included in the name, the default
package name is used.

The symbol @ with the event connection can be added after the event name. you can
also use the event range and a wildcard to indicate an event name. the wildcard *
represents “all” while the wildcard $ represents “current or any”.

Each signal has an associated signal type, such as on/off (OO), timeout (TO), and
brief (BR).

Table 5-1 lists some basic packages.