H.323 (H323)

1. Introduction VoIP

2. RTP (Real-time Transport Protocol)

• Payload Types
• RTP Timestamps
• Silence Supression
• Supporting Real-time Traffic
• The first Voice Packet
• The second voice Packet
• The third Voice packet
• A Jitter buffer operation
• The adaptive Jitter Buffer Example
• RTP Sequence
• Synchronization source
• Contribution Source (CSRC)
• DTMF (RFC2833)
• Telephony tones & signals (RFC 2833)
• RTP Packet-Using Ethereal, find all these RTP fields
• RTCP – (RTP Control protocol)
  1.Source descriptions SDES
  2.Sender reports SENDER
  3.Receiver reports RECEIVER
  4.RTCP Calculates Round Trip
  5.RTCP Bye Report
  

3. ASN.1RTP (Real-time Transport Protocol)

• Sending data, not the format
• ASN.1 basics
• ASN.1 Modules
• Basic Encoding Rules (BER)
• Packed Encoding Rules (PER)
• ASN.1 Exercise
  1.Decode an H.245 terminalCapabilitySet Message
  2.How to reference H.245 Annex A
  3.OID
  4. H.323 Architecture

• H.323 stack
• H.323 Components
  1.Terminal
  2.MCU
  3.Gateway
  4.Gatekeeper
  5.Border Element
  
• Gatekeeper Zone
• Relationship between H.323 and H.248
• H.323 Administrative Domain
• RAS vs Annex G

5. RAS

• RAS and other H.323 protocols
• RAS Request/response
• RAS message set
• RAS at layer 4
• RAS at layer 3
• Close look at popular RAS messages
  1.GRQ-GCF/GRJ exchange
  2.Gatekeeper discovery
  3.RRQ-RCF/RRJ exchange
  4.LW RRAQs
  5.ARQ-ACF/ARJ exchange
  6.LRQ-LCF/LRJ
  7.BRQ-BRF/BRJ exchange
  8.DRQ-DCF/DRJ
  9.IRQ-IRR
  10.RAAI-RAC
  11.SCI-SCR
  

6. H.225.0

• Usage of Q.931
• Q.932 messages supported/forbidden
• Q.922 messages
• Direct endpoint signalling
• Gatekeeper routing
• Direct endpoint signaling, only called endpoint registered
• Call example with both endpoints registered across multiple zones
• Call example using multiple zones and LRQ/LCF
• RSVP Sync

7. H.245

• H.245 overview
• H.245 tunneling
• Call setup example using RAS, call signalling channel, and H.245
• Terminal Capability exchange
• Master/Slave determination
• Logical Channel signalling
• Overlap dialing
• The capability table
• Simultaneous capabilities
• Capability descriptors
• The role of the master

8. Fast Connect Procedure

• SETUP
• CALL PROCEEDING
• PROGRESS
• FastStart procedure

9. T.38 and H.323

• The T.38 process
• Reading a T.38 decode

10. H323 Versions

• Version 2
• Version 3
• Version 4
• Version 5

11.Labs.