G.723.1 is an audio codec for voice that compresses voice audio in 30 ms frames. An algorithmic look-ahead of 7.5 ms duration means that total algorithmic delay is 37.5 ms. Its official name is Dual rate speech coder for multimedia communications transmitting at 5.3 and 6.3 kbit/s.

This is a completely different codec from G.723.

There are two bit rates at which G.723.1 can operate:


G.723.1 is mostly used in Voice over IP (VoIP) applications due to its low bandwidth requirement. Music or tones such as DTMF or fax tones cannot be transported reliably with this codec, and thus some other method such as G.711 or out-of-band methods should be used to transport these signals. The complexity of the algorithm is below 16 MIPS. 2.2 kilobytes of RAM is needed for codebooks.

G.723.1 is a required audio codec in the H.324 ITU-T recommendation for H.324 terminals offering audio communication. In 3GPP 3G-324M specification support for G.723.1 is not mandatory, but recommended.



Use of G.723.1 requires a license for the patents that cover the algorithm.

The authorized intellectual property rights (IPR) Licensing Administrator for G.723.1 technology is Sipro Lab Telecom.[1][2][3]

Members of the G.723.1 patent pool are AudioCodes, France Telecom, Université de Sherbrooke, Nippon Telegraph and Telephone Corporation and Nokia.[4]

See also


  1. VoiceAge Corporation (2007-10-14). "G.723.1 Licensing". Archived from the original on 2007-10-14. Retrieved 2009-09-17.
  2. Sipro Lab Telecom (2007-10-25). "FAQ G.729 and G.723.1". Archived from the original on 2007-10-25. Retrieved 2009-09-17.
  3. Sipro Lab Telecom (2006-10-29). "G.723.1, the highest ITU-T compression ratio". Archived from the original on 2006-10-29. Retrieved 2009-09-17.
  4. Sipro Lab Telecom (2006-10-29). "G.723.1 - Members". Archived from the original on 2006-10-29. Retrieved 2009-09-17.

External links

This article is issued from Wikipedia - version of the 8/28/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.