# Standards

The following International Telecommunications Union (ITU) specifications and Networking Group RFCs provide detailed information about T.38 facsimile, RTP, and voice media coders:

Document | Description | Date
ITU-T Recommendation G.711 | Pulse code modulation (PCM) of voice frequencies | 1988
ITU-T Recommendation G.723.1 | Dual rate speech coder for multimedia communication transmitting at 5.3 and 6.3 kbit/s | 1996
ITU-T Recommendation G.729 | Coding of speech at 8 kbit/s using conjugate structure algebraic-code-excited linear-prediction (CSACELP) Annex A: Reduced complexity 8 kbit/s CS-ACELP speech codec | 11/96
ITU-T Recommendation G.726 | 40, 32, 24, 16 kbit/s Adaptive Differential Pulse Code Modulation (ADPCM) | 12/90
IETF Internet RFC 1889 | A Transport Protocol for Real-Time Applications | 1/96
IETF Internet RFC 1890 | RTP Profile for Audio and Video conferences with Minimal Control | 1/96
ITU-T Recommendation T.38 | Procedures for Real Time Group 3 Facsimile Communications over IP Networks | 6/98
IETF Internet RFC 2833 | RTP Payload for DTMF Digits, Telephony Tones and Telephony Signals | 5/2000
IETF Internet RFC 2464 | A Method for Transmission of IPv6 Packets over Ethernet Networks | 12/1998