[Asterisk-Dev] IAX2 protocol question

[Tim Robbins]

Matt Riddell wrote:

> Tim Robbins wrote:
>
>>  From reading the Asterisk sources, it looks as if the FORMAT 
>> information element, when sent as part of an ACCEPT frame, lets the 
>> calling IAX endpoint know which formats are supported by both 
>> parties. However, libiax2 (and therefore the majority of IAX 
>> softphones) does not send a FORMAT IE as part of the ACCEPT. In this 
>> situation, what is the "right" way to determine which format voice 
>> frames should be sent in?
>>
>> Thanks for any suggestions.
>
>
> The iaxclient libraries have just recently had multiple codecs added. 
> You might want to check that you have the latest version.

I was actually more interested in how codec negotiation is supposed to 
work in the IAX2 protocol itself (and specifically, what an endpoint 
should do if the ACCEPT frame is missing a FORMAT IE), not any 
particular implementation.


Tim