0aa000006 h.323 protocol issue2.0

7/30/2019 0aa000006 h.323 Protocol Issue2.0

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ISSUE

Fixed Network Curriculum

Development Section

OAA000006 H.323 ProtocolPrinciple

2.0


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Confidential Information of Huawei.No Spreading without Permission. Security Level: Internal

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Objectives

Know functions of H.323 protocols

and their components

Understand commands of H.323

protocols

Understand meanings and usage of

the parameters in H.323 commands

Know communication process of

H.323 protocols and functions of

various protocols in the whole

communication process

Upon completion of this course, you will be able to:


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References

Product Manual - Technical Manual - Signaling and

Protocols - Chapter 7 H.323


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Course Contents

Chapter 1 Overview

Chapter 2 RAS Protocol

Chapter 3 Q.931 Protocol

Chapter 4 H.245 Protocol

Chapter 5 Call Signaling Procedure


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Protocol Stack

In SoftX3000, RAS, Q.931 and H.245 in H.323 protocol suite

are used. RAS (Registration, Admission, and Status)

The protocol for communications between GW and GK. It is

used for GW registration and authentication.

Q.931

The protocol for communications between GW and GK. It

processes signaling during the session. It is belongs to the

H.225.0 protocol

H.245

The protocol used for communications between calling and

called GWs. It includes the following three aspects:

master/slave control, capability exchange, opening or closing

of logical channel.


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RAS s main-functions

Gatekeeper Discovery GRQ

Registration Message RRQ

Unregister Message URQ

Admission Message ARQ

Disengage Message DRQ

Address Resolution Request Messages LRQ

Bandwidth Modification Messages BRQ Status Messages IRQ

Gateway Resource Availability Messages RAI


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Message Process

Gatekeeper discovery:

Terminal GK

GRQ

GCF

GRJ


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Course Contents

Chapter 1 Overview






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Basic Call Setup - Direct Routing

Terminal1

Setup

Connect

CallProceeding

Alerting

Terminal2

TCP Connection setup

Q.931 Call signaling channel

GK

ARQ

ACF


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Basic Call Setup - GK Routing

Setup

Connect

CallProceeding

Alerting

TCP connection setup

GK

ARQ

ACF

Terminal1 Terminal2

Setup

CallProceeding

TCP connection setup

Alerting

Connect


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Course Contents

Chapter 1 Overview






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Overview

Recommendation H.245 specifies in details signaling messages

and procedure syntax and semantics for H.323 endpoints. These

messages and procedures, which covers endpoint receive and

transmit capability, mode requirements for the receive endpoint,

logical channel signaling, control and indication, may be negotiated

in-band at the beginning of or during the session.

The H.245 Control Channel carries endpoint-to-endpoint control

messages governing operation of the H.323 entity, including:

Master-slave determination

Capability exchange

Opening and closing of logical channels


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Capability Exchange

Terminal1 Terminal2

TCSReq

TCSAck

TCSRej

TCSRelTimeout


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Master-slave Determination

Terminal1 Terminal2

MSDReq

MSDAck

MSDRej

MSDRelTimeout


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Close Logical Channel

Terminal1 Terminal2CLC

CLCAck

CLCRej

CLCRelTimeout


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End Session

Terminal1 Terminal2

ECS

TCP connection clearing

ECS


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Signaling Coordination

An H.323 call can be set up in either normal start or fast

start mode. And RAS, Q.931 and H.245 may be used in

conjunction.


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Typical Call Procedure - Normal Start (Cont.)

DRQ

DCFDRQ

DCF

EndSessionCommand

Disconnect H.245TCP connection

Close logic channel

EndSessionCommand

ReleaseComplete

Disconnect Q.931TCP connection

Terminal1 Terminal1GK


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Typical Call Procedure - Fast Start

AR

QACF

ARQ

ACF

Q.931 TCP Connection

Setup(OLC)

Alerting

CallProceeding

Connect(OLC)

DRQ

DCF DRQ

DCF

ReleaseComplete

Disconnect Q.931TCP connection

Terminal1 Terminal2GK


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