G.729 Codec License Usage with IP Trunks


Good Morning All,
Based on the below license link about G.729, could some one answer this question regarding Pass-Thru usage:

If I connect an Asterisk server to an AVAYA CM via an H.323 IP Trunk and that trunk uses G.729 Codec as a compression standard, that then connects to another AVAYA CM via a SIP Trunk using G.729 as the compression standard. Do I need to purchase a License or being that both inherently support G.729 is this considered a Pass Thru Call?

Basically I am using the Asterisk as the Gateway between the systems.

voip-info.org/wiki/view/Aste … +pass-thru

Thank you All for your assistance.


Depends on whether you source any tones, or want to do voice recording.

Also, you need to be careful with originate, as it defaults to a signed linear codec. Same for call files.


Thank you for the response and information. I am not doing any voice recording, this would just be an IP Trunk from an AVAYA CM to another AVAYA CM or AVAYA Endpoint that inherently uses G.729 as a codec( i.e. IP Phone)./ If I read the license correct because it is inherent in the devices they should not use a license./

Thank you.


You need to look at the actual dialplan.

If you explicitly call Answer or Progress in the dialplan, there is a good chance you will consume a licence, or the caller will fail to here a call progress tone.