1. OpenH323 Open source internet videoconferencing www.openh323.org Jeremy Medow Presented to: Dr. Dennis Anderson and team 6/10/02

2. OpenH323 General Information Protocol Language Codecs

3. Based on the H.323 protocol –Same protocol used by Microsoft Netmeeting Many standalone videoconferencing units –Developed by the ITU (www.itu.int)www.itu.int –Most recent accepted protocol OpenH323 Protocol

4. Written in C++ –Entirely open source Any or all of the program can be used freely –Code can be downloaded from http://www.openh323.org/code.html. http://www.openh323.org/code.html –If the openh323 library is used strictly as a library, a commercial product can be produced OpenH323 Language

5. Codecs –Supports G.711 and GSM audio codecs –Supports H.261 video codec OpenH323 Codecs

6. OpenH323 Capabilities Programs Interfaces Platforms

7. OpenPhone, OhPhone –Endpoint clients OpenMCU –Multipoint control unit OpenGK –Gatekeeper Others –Answering machine, gateway, etc. OpenH323 Programs

8. GUI –OpenPhone has a graphical user interface More user friendly Command Line –OhPhone has a command line interface More flexible, powerful OpenH323 Interfaces

9. GUI client for Windows –OpenPhone Command line client for Windows, Linux –OhPhone MCU, Gateway for all platforms –OpenMCU, PSTNGw OpenH323 Platforms

10. OpenH323 H.323 Details Architecture Multipoint Streams Channels

11. Terminals –Client endpoints: interface, etc. Gateways (optional) –Translation, call setup Gatekeepers –Call control, Bandwidth management, routing Multipoint Control Units –Manage 3+ endpoint communications OpenH323 Architecture

12. MCU is actually two components –MC (Multipoint Controller) Deals with connection protocols Chooses stream (audio/video/data) destinations –MP (Multipoint Processor) Mixes/switches streams Transmits streams to appropriate destinations MCU can be standalone or embedded within endpoints OpenH323 Multipoint

13. Types of multipoint control –Centralized All streams are sent to MCU –MC manages streams –MP mixes, distributes streams –Decentralized Audio, Video are multicast to, from all endpoints Data, call control information sent to MCU –Hybrid Mix of Centralized and Decentralized OpenH323 Multipoint (cont’d)

14. Control –H.245: Capabilities, channel management –Q.931: Establishes connections –RAS: Bandwidth changes, status, disengage Audio –G.771: Voice compression Video –H.261: Video codec (H.263 possible) Data (Whiteboard, data sharing, file transfer) –T.120: Can be used by endpoints, mixed by MCU OpenH323 Streams

15. Two channels –Reliable (TCP): Accurate Control channel (H.245) T.120 Data channel Call signaling channel (Q.931) –Unreliable (UDP): Faster Audio stream Video stream RAS channel (only with gatekeeper) OpenH323 Channels

16. OpenH323 More Information OpenH323 H.323 details

17. www.openh323.org –Information on OpenH323 Capabilities, updates Licensing details –Downloads Source code (C++) Executables –Links Information on H.323 OpenH323

18. www.packetizer.com/iptel/h323 –Papers & Presentations An H.323 primer Multipoint information –General information –Links OpenH323 H.323 details

19. OpenH323 Open source internet videoconferencing www.openh323.org