Codec error (g729) error between Asterisk proxy and CPE
We do use G729a from Digium on our Asterisk servers. Yes, we tried to set G729a on Wellgate and other x already. We tried almost every possible route to get G729a to work, but are unsuccessful. Please try it on your Asterisk system and let us know. I doníŽt believe it will work simply because when we sniff the packet coming from the wellgate is ulaw not G729a even we configured as G729a. It since to me this is Wellgate firmware issue. As far as I know Wellgate does have issue working with Asterisk in their pervious firmware version for specific feature set, because they use non RFC standard. ThatíŽs why they have a new firmware version that is compatible with Asterisk. If you can get them to work with you to resolve this it will be great.
I checked this problme with your platform and i found this problem is due to the codec priority is incorrect in SDP of 200 OK from proxy.
You can check the no.69 packet, this is a 200OK from proxy.
You can expand this packet and check the detailed parameters of SDP.
You can found the proxy still sent the G711 as the first priority ( the g729 is under 3rd priority).
So the FXO still sent the G711 codec although it only set on g729, because of the server set the G711 as the 1st priority.
So i think you can check the proxys configuration first.
Change the order of G729 as first priority.