Codec Options:

  • G.711: Most common codec (ulaw/alaw), 64 kbit/s bitrate, free
  • G.729: Second most common codec, 8kbit/s bitrate, $ licensed
  • GSM: Common low bandwidth codec, 13 kbit/s bitrate, free
  • Many others with lower bitrates to higher bitrates for better quality
  • .
      • .711
      • LPC10
      • GSM
      • iLBC
      • G.726
      • G.722
      • ADPCM

Codecs reside in /usr/lib/asterisk/modules

You need to download the appropriate codec for your CPU

cat /proc/cpuinfo

and look your cpu up to get an idea for codec


Download G.729 codec


copy link for your asterisk version


Go down to


module load and module unload is used in asterisk to load or unload codecs

If you want to use a specific codec for extensions or SIP Carrier

vi /etc/asterisk/sip.conf

edit allow=ulaw to allow=g729


add the allow=ulaw as a failback incase carrier doesn’t support G729

Included with Asterisk