I am struggling with Asterisk’s method of negotiating appropriate codecs. Every time I think I have it figured, something happens that makes me realise I haven’t.
Can someone please tell me the priority of codec selection.
E.G. I have a SIP ISDN gateway (Tenor BX) which is set to use G.729 as first priority and G.711a as second priority.
All phones are set the same.
I have an ATA with a fax machine attached that has only the G.711 coded in its preference list (for obvious reasons).
In sip.conf, I have allow in order of g729 ilbc g711a.
In my ata context I have allow g711 and disallow all
From this am I safe to assume that all calls TO AND FROM the ATA will be G711?
When I bring up conversations between endpoints sip show channels seems to be something other than what I expect. One device is using G.729 and the other is using G.711 on the same conversation.
If anyone can shed light on this, or point me to a good document on setting codecs I would be grateful. I really want different codecs to be used in different situations based on endpoint locations/capabilities, etc.
Can someone please tell me exactly what