iLBC is a VOIP codec originally created by Global IP Sound but made available (including its source code) under a restricted but free and fairly liberal license, including permission to modify.

Quoted from:

What is iLBC?
  • iLBC (internet Low Bitrate Codec) is a FREE speech codec suitable for robust voice communication over IP. The codec is designed for narrow band speech and results in a payload bit rate of 13.33 kbit/s with an encoding frame length of 30 ms and 15.20 kbps with an encoding length of 20 ms. The iLBC codec enables graceful speech quality degradation in the case of lost frames, which occurs in connection with lost or delayed IP packets.

  • Bitrate 13.33 kbps (399 bits, packetized in 50 bytes) for the frame size of 30 ms and 15.2 kbps (303 bits, packetized in 38 bytes) for the frame size of 20 ms
  • Basic quality higher than G.729A, high robustness to packet loss
  • Computational complexity in a range of G.729A
  • Royalty-free Codec


  • 2008-04-02 - iLBC no longer included with Asterisk source (1.4.19 and 1.6);
    • to install ilbc codec translation:

cd /usr/src/asterisk/
cp /usr/src/asterisk/contrib/scripts/codecs /usr/src/asterisk/codecs/

selection 4 (codecs)
to make sure ilbc selected
exit + save


asterisk -rvvvvvvvvvvvv
core show translations

  • 2004-12-06 - Internet Engineering Task Force (IETF) has approved standardization of the iLBC codec.
  • 2004-11-23 - GIPS to Provide Major DSP Chip Manufacturer Infineon with iLBC Speech Codec to Accelerate Time-to-Market Press Release
  • 2004-08-09 - GIPS iLBC has been specified as a mandatory codec in the recently released CableLabs PacketCableTM 1.1 Audio/Video Codec

See Also

Created by: jht2, Last modification: Mon 06 of Dec, 2010 (15:22 UTC) by rkelley
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