1. H.323 Overview Demystifying Multimedia Conferencing Over the Internet Using the H.323 Set of Standards

2. Numbers to know: H.225 - call setup, establishment, tear-down H.245 - media capability negotiation H.261 & H.263 - video codecs G.7xx - audio codecs

3. H.323 Architecture Audio and Video codecs H.225 Layer H.245Q.931RAS Audio and Video I/O

4. How does all this work? ( the signaling example )

5. How does all this work? Calling party opens H.323 client

6. How does all this work? Q.931 Setup Setup

7. How does all this work? Q.931 Alerting (ringing) Alerting

8. How does all this work? Q.931 Connect Connect

9. How does all this work? H.245 terminal capabilities termCapSet

10. How does all this work? H.245 terminal capabilities termCapAck

11. How does all this work? H.245 determine Master/Slave mSDet

12. How does all this work? H.245 determine Master/Slave mSDetAck

13. How does all this work? H.245 determine Master/Slave mSDetConfirm

14. How does all this work? H.245 open channel (RTP) openReq

15. How does all this work? H.245 open channel (RTP) openAck

16. How does all this work? RTP connection connected

17. How does all this work? H.245 End Session endSession

18. How does all this work? Q.931 Release Complete ReleaseComplete

19. Gatekeeper Purpose is to manage resources in a zone Uses RAS signaling Provides address resolution Alias Address Modification Approves calls based on bandwidth Dialed Digit Translation (PSTN) Directory Services

20. Advanced Features Interoperability with PSTN Centralized, decentralized, and hybrid multicast conferences through MCU Datastream and multicast encryption (H.235) Cascading MC’s for large conferences FastStart connection (similar to SIP)

21. H.323 Issues Interoperability issues between clients Massive, monolithic, closed specification Not designed to be readily extensible Competition from simpler, open, IETF standards (SIP, SDP, RTP)

22. Why is this important? Stress test of real latency sensitive data H.323 central to QoS issues Authentication carried out through CiNIC?