About this page ...

I was working in the VoIP area both at STMicroelectronics/Singapore and then at Aztech/Singapore, in the SIP protocol and associated applications.  Not maintained anymore.

VoIP (Voice over Internet Protocol)


VoIP related standards/RFCs

  • RFC3550 RTP: A Transport Protocol for Real-Time Applications (Obsoletes: RFC1889)
  • RFC3551 RTP Profile for Audio and Video Conferences with Minimal Control (Obsoletes: RFC1890)
  • RFC2198 RTP Payload for Redundant Audio Data
  • RFC3389 RTP Payload for Comfort Noise
  • RFC2833 RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals
  • G.165 - Echo Cancellers (latest: 03/1993)
  • G.168 - Digital Network Echo Cancellers (latest: 08/2004)
  • G.711 - Pulse code modulation (PCM) of voice frequencies (11/1988)
  • G.711 Appendix I - A high quality low-complexity algorithm for packet loss concealment with G.711 (09/1999)
  • G.711 Appendix II - A comfort noise payload definition for ITU-T G.711 use in packet-based multimedia communication systems (02/2000)
  • G.723.1 - Dual rate speech coder for multimedia communications transmitting at 5.3 and 6.3 kbit/s (05/2006)
  • G.726 - 40, 32, 24, 16 kbit/s Adaptive Differential Pulse Code Modulation (ADPCM) (12/1990)
  • G.729 - Coding of speech at 8 kbit/s using conjugate-structure algebraic-code-excited linear prediction (CS-ACELP) (03/1996)
  • G.729 Annex A - Reduced complexity 8 kbit/s CS-ACELP speech codec (11/1996)
  • 802.1D - IEEE standard for local and metropolitan area networks--Media access control (MAC) Bridges (Incorporates IEEE 802.1t-2001 and IEEE 802.1w) (latest: 2004)
  • 802.1P - IEEE Standard for Local and Metropolitan Area Networks—Supplement to Media Access Control (MAC) Bridges: Traffic Class Expediting and Dynamic Multicast Filtering. (Note: Later it has been incorporated into 802.1D. See Appendix G of 802.1D. You will not see any separate document called 802.1P)
  • 802.1Q - IEEE Standards for Local and metropolitan area networks—Virtual Bridged Local Area Networks (latest: 2003)


SIP Related Important RFCs
  • RFC2543 Core SIP Specification (obsoleted by RFC3261)
  • RFC3261 Core SIP Specification
  • RFC3262 Reliability of Provisional Responses in Session Initiation Protocol (SIP)
  • RFC3263 Session Initiation Protocol (SIP): Locating SIP Servers
  • RFC3264 An Offer/Answer Model with Session Description Protocol (SDP)
  • RFC3265 Session Initiation Protocol (SIP)-Specific Event Notification
  • RFC2327 SDP: Session Description Protocol (obsoleted by RFC4566)
  • RFC4566 SDP: Session Description Protocol
  • RFC2976 The SIP INFO Method
  • RFC3515 The Session Initiation Protocol (SIP) Refer Method
  • RFC3311 The Session Initiation Protocol UPDATE Method
  • RFC3489 STUN - Simple Traversal of UDP Through Network Address Translators
  • RFC3326 The Reason Header Field for the Session Initiation Protocol (SIP)
  • RFC3361 DHCP Option for SIP Servers
  • RFC3842 A Message Summary and Message Waiting Indication Event Package for the Session Initiation Protocol (SIP)
  • RFC4475 SIP Torture Test Messages

Fax over IP - FoIP



H.248 - Megaco