[asterisk-users] SIP Codec negotiation

Steve Edwards asterisk.org at sedwards.com
Fri May 11 08:36:56 CDT 2018

On Fri, 11 May 2018, Joshua Colp wrote:

>> In the above example, even though the INVITE/SDP says they prefer gsm 
>> over ulaw and the OK/SDP says I prefer ulaw over gsm, they can choose 
>> to use gsm or ulaw?
> Yes.
>> Can it be asymmetrical? They send gsm and I send ulaw?
> Technically, yes. In practice it's a bit iffy - specifically because 
> some DSPs in devices won't allow it - they require a single codec be in 
> use for each direction.

So, Asterisk will defer it's choice of codec to match the codec it detects 
in the incoming stream?

Thanks in advance,
Steve Edwards       sedwards at sedwards.com      Voice: +1-760-468-3867 PST

More information about the asterisk-users mailing list