[Asterisk-Users] Re: [Iaxclient-devel] codec negotiation ?

[Gary]

On Thu, 08 Apr 2004 10:14:09 -0400, Steve Kann wrote:

>Gary wrote:
>
>>I have noticed lack of codec negotiation with calls thru a registrated
>>asterisk box.
>>
>>No seen problems with outbound calls, (though I haven't specifically
>>tried it), but the problem exists inbound.
>>
>>Easiest method for testing this was ring in via a sip client set to
>>ulaw, ringing a registered iaxcomm extension.
>>
>>currently using iaxcom-win-20040228
>>
>>
>>
>>I might add DIAX.097a continually bombs out on making calls as well.
>>
>>current machine here is a compaq 910a running xp-home.
>>
>>Any thoughts of what I might have missed ??
>>  
>>
>
>You forgot to write the code to support multiple codecs :)
>
>Ok, seriously -- iaxclient currently supports only GSM.  Nobody has 
>stepped up to write the code necessary to support multiple codecs.  At 
>some point, I probably will, if only because I spend more time talking 
>about it than it would take to do it.
>
>On a similar note, I benchmarked GSM vs Speex vs ILBC.  GSM is fastest 
>to encode, but speex is fastest to decode.  Speex and ILBC are similar 
>in encode speed.  (Speex encode speed depends on the quality/bitrate 
>settings you use; ILBC/GSM have no such settings).
>
>Speex would be easiest to do (along with uLaw), but it shouldn't be much 
>harder to include iLBC (just need to ensure the 30ms frames are dealt 
>with), except for licensing issues (you can't use iLBC with GPL, for 
>example).
>
>Back to your question, though:  Asterisk should translate codecs for you 
>in this case, as your call from Sip-client to iaxclient needs to go 
>through asterisk.  There may be a setting in iax.conf to tell asterisk 
>we only support GSM. [but we probably should be able to tell asterisk 
>this in our protocol exchange].

This is something which seems to be missing (maybe) in asterisk....

I haven't been doing much with thus stuff lately, but if on setting a
registration in IAX.con it would be nice to actually list there which
codecs are allow for this client on an individual basis, same for
SIP.conf etc...


.