T 120 data protocol for multimedia conferencing
Download
1 / 24

T.120 : Data Protocol for Multimedia Conferencing - PowerPoint PPT Presentation


  • 606 Views
  • Uploaded on

T.120 : Data Protocol for Multimedia Conferencing. Advanced multimedia 4/27/1999 Jeong, Hwanseok [email protected] Contents. Overview Normative references Introduction to Multimedia Communication The T.120 System Model T.120 Infrastructure Recommendation

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'T.120 : Data Protocol for Multimedia Conferencing' - Leo


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
T 120 data protocol for multimedia conferencing l.jpg

T.120 : Data Protocol for Multimedia Conferencing

Advanced multimedia

4/27/1999

Jeong, Hwanseok

[email protected]

Multimedia & Communication Lab.


Contents l.jpg
Contents

  • Overview

  • Normative references

  • Introduction to Multimedia Communication

  • The T.120 System Model

  • T.120 Infrastructure Recommendation

  • Application Protocol Recommendation

  • T.120 Compliance

  • References

Multimedia & Communication Lab.


Normative reference l.jpg
Normative reference

  • ITU-T Recommendation T.121(1996), Generic Application Template

  • ITU-T Recommendation T.122(1993), Multipoint Communication Service for Audiographic and Audiovisual Conferencing service definition

  • ITU-T Recommendation T.123(1993), Protocol Stack for Audiographics and Audiovisual Teleconference Application

  • ITU-T Recommendation T.124(1995), Generic Conference Control

  • ITU-T Recommendation T.125(1994), Multipoint Communication Service Protocol

  • ITU-T Recommendation T.126(1995), Multipoint Still Image and Annotation Protocol

  • ITU-T Recommendation T.127(1995), Multipoint Binary File Transfer Protocol

Multimedia & Communication Lab.


Overview l.jpg
Overview

  • T.120 recommendation series : multipoint communication service for use in multimedia conferencing environments

  • T.120

    • Introduction for the T.120 series, showing the inter-relationships between the constituent recommendation

    • requirements for compliance to T.120 for conferencing

Multimedia & Communication Lab.


Introduction to multipoint multimedia communication l.jpg
Introduction to Multipoint Multimedia Communication

  • Multipoint communication : interconnection of multiple terminals

  • MCU(Multiple Control Unit), or more simply a bridge, is required

  • T.120 series : the components providing both a data communications service, and a management service for any other media services present

  • MCU

    • nodes without terminal functionality, acting as bridging nodes, bridging data and other media streams present in the connections

Multimedia & Communication Lab.


Introduction to multipoint multimedia communication cont d l.jpg
Introduction to Multipoint Multimedia Communication(cont’d)

< Examples of Multipoint conference configurations showing

various connection topologies and Node types >

Terminal

Terminal

Point to point

(The simplest case of a multipoint connection)

Terminal

Multiport

terminal

Multiport

terminal

Terminal

Chain Connection with terminals acting as data bridges

Multimedia & Communication Lab.


Introduction to multipoint multimedia communication cont d7 l.jpg
Introduction to Multipoint Multimedia Communication(cont’d)

MCU

Terminal

MCU

MCU

Terminal

Terminal

Terminal

Terminal

Terminal

< Multipoint topology-3 MCUs providing connection to allow multiple

terminal to participate in a conference >

Multimedia & Communication Lab.


Introduction to multipoint multimedia communication cont d8 l.jpg
Introduction to Multipoint Multimedia Communication(cont’d)

Public Network

Corporate Network A

Terminal

Terminal

LAN Gateway

-Router-

ISDN

ISDN

Terminal

Terminal

Terminal

ISDN

MCU

MCU

PSTN

ISDN

Corporate Network B

LAN Gateway

-Router-

Terminal

PSTN

Terminal

Terminal

Terminal

Terminal

Terminal

PSTN

< Example of a mixed-network conference topology >

<

Multimedia & Communication Lab.


T 120 system model l.jpg
T.120 System Model Communication(cont’d)

User Application(s)

(Using Both Standard and Non-standard Application Protocols

User Application(s)

(Using Std. App. Protocol)

Node

Controller

User Application(s)

(Using Non-std. Protocol)

T.127 (MBFT)

T.126(MSIA)

Application Protocol Entity

Non-Std. App.

Protocol Entity

ITU-T T.120 Application

Protocol Recommendation

Generic Conference Control(GCC) T.124

Multipoint Communications Service(MCS) T.122/125

Network Specific Transport Protocols T.123

ITU-T T.120 Infrastructure Recommendatios

Multimedia & Communication Lab.


T 120 system model cont d l.jpg
T.120 System Model(cont’d) Communication(cont’d)

  • Comprised of a communications infrastructure and the application protocols

  • User Application

    • use the services offered by the T.120 series

    • will generally be multipoint aware and designed to use the T.120 services by GCC and MCS

    • T.121(Generic Application Template) provide on how to utilize the T.120 infrastructure in a consistent way

Multimedia & Communication Lab.


T 120 system model cont d11 l.jpg
T.120 System Model(cont’d) Communication(cont’d)

  • Application Protocols

    • Protocol Data Units(PDUs) + actions for App. peer-to-peer communication

    • The T.120 series includes application protocols designed to support multipoint conferencing

    • Application Protocol Entity

      • an instance of an Application Protocol

      • ARM(Application Resource Manager) + ASE(Application Service Element)

      • ARM : generic functionality relevant to all protocols

      • ASE : application specific functionality

      • Both of these are described in T.121(Generic App. Template)

Multimedia & Communication Lab.


T 120 system model cont d12 l.jpg
T.120 System Model(cont’d) Communication(cont’d)

  • Node Controller

    • T.120 management role at a terminal or MCU

    • issue primitives to the GCC provider which starts and control the communication session : outside the scope of the T.120

  • Communication Infrastructure

    • multipoint connectivity with reliable data delivery

    • Three components : GCC, MCS, Transport Protocol Profile

  • Networks

    • ISDN : Integrated Services Digital Nerwork

    • CSDN : switched or permanent digital circuits

    • PSDN : Packet Switched Data Network using X.25

    • PSTN : Public Switched Telephone Network

    • B-ISDN, LAN under study

Multimedia & Communication Lab.


T 120 infrastructure recommendation l.jpg
T.120 Infrastructure Recommendation Communication(cont’d)

  • Protocol Stacks for Audiographic and Audiovisual conferencing - T.123

  • Multipoint Communication Service(MCS) - T.122, T.125

  • Generic Conference Control (GCC) - T.124

Multimedia & Communication Lab.


T 123 protocol stacks for audiographic and audiovisual conferencing l.jpg
T.123 : Protocol Stacks for Audiographic and Audiovisual conferencing

  • Network specific transport stacks for each supported network

  • MCS takes the transport pairs from the layer below it and maps them into a multipoint domain

Network

Independent

Layer

T.125 - Multipoint Communications Service(MCS)

Network

Dependent

Layer

ISDN

Transport

CSDN

Transport

PSDN

Transport

PSTN

Transport

B-ISDN

Transport

NLAN

Transport

Multimedia & Communication Lab.


T 122 t 125 multipoint communication service mcs l.jpg
T.122, T.125 : Multipoint Communication Service(MCS) conferencing

  • T.122 : defines the MCS service

  • T.125 : specifies the data transmission protocol

  • MCS : multipoint “engine” of the T.120 conference

  • takes point-to-point transport connections provided by the layer below it and combine to form a multipoint domain

  • MCS Provider(Top Provider) acting as the resource server for the domain

  • MCS app direct data within domain via the use of channel

  • token are the last major facility provided by MCS

    • services are provided to grab, pass, inhibit, query token

Multimedia & Communication Lab.


T 124 generic conference control gcc l.jpg
T.124: Generic Conference Control(GCC) conferencing

  • Comprehensive set of facilities for establishing and managing the multipoint conference

  • to maintain information about the nodes and applications that are in a conference

  • Applications create conferences, join conferences, and invite others to conference

  • conference security

  • capabilities for supporting the concepts of conductorship in a conference

Multimedia & Communication Lab.


Application protocol recommendation l.jpg
Application Protocol Recommendation conferencing

  • The Generic Application Template(GAT) - T.121

  • Multipoint Still Image and Annotation Protocol(MSIA) - T.126

  • Multipoint Binary File Transfer(MBFT) - T.127

  • Non-Standard Application Protocols

Multimedia & Communication Lab.


T 121 the generic application template gat l.jpg
T.121 : The Generic Application Template(GAT) conferencing

  • A conceptual model of a T.120 application protocol

  • A guide to application protocol developers and user application developers on how to utilize the T.120 infrastructure to best effect

  • Two distinct parts

    • ARM(Application Resource Manager) + ASE(Application Service Element)

    • ARM : generic functionality relevant to all protocols

    • ASE : application-protocol-specific functionality

    • Both of these are described in T.121(Generic App. Template)

Multimedia & Communication Lab.


T 126 multipoint still image and annotation protocol msia l.jpg
T.126 : Multipoint Still Image and Annotation Protocol(MSIA)

  • To be used by a broad set of user application that require inter-operable graphical information exchange in a multi-vendor environment

  • white boarding, annotated image exchange, hard copy image exchange, remote computer application piloting, screen sharing

  • manage the conference-wide synchronization of multi-plane/multi-view graphical workspaces

  • Advanced option

    • keyboard and pointing device signaling

Multimedia & Communication Lab.


T 127 multipoint binary file transfer mbft l.jpg
T.127 : Multipoint Binary File Transfer(MBFT)

  • to support interchange of binary files within an interactive conferencing or group working environment

  • no restriction on the content of the files to be transferred

  • versatile

  • flexible

  • Optional advanced feature

    • Broadcast of multiple files simultaneously

    • Private distribution of files to a selected subset of the conference

    • Conductor control of file distribution

Multimedia & Communication Lab.


T 127 multipoint binary file transfer mbft21 l.jpg
T.127 : Multipoint Binary File Transfer(MBFT)

Node that require

files A and B

Node that

require file A

MBFT

MBFT

MBFT

MCS

Provider

Top MCS

Provider

MCS

Provider

MCS

Provider

Data channel

Control channel

Multimedia & Communication Lab.


Non standard application protocols l.jpg
Non-Standard Application Protocols

  • Must use GCC in a way that does not risk conflict with other app. protocol entity

Multimedia & Communication Lab.


T 120 compliance l.jpg
T.120 Compliance

  • transport Protocol stack profile(T.123)

  • multipoint Communication Service protocol(T.125)

  • mandatory parts of Generic Conference Control(T.124)

  • mandatory parts of any standardized app. Protocol

Depend on condition

T.121

conditional

mandatory

T.123

T.124

mandatory

Depend on condition

T.125

mandatory

T.126

conditional

Depend on condition

T.127

conditional

Depend on condition

Multimedia & Communication Lab.


References l.jpg
References

  • ITU-T Recommendation T.120(1996), Data Protocol for Multimedia Conference.

  • “A Primer on the T.120 Series Standard”, http://www.databeam.com/ccts/

Multimedia & Communication Lab.


ad