My customer is having an IP link to make international VoIP calls. The codec used in these trunk is G.729. But the problem is that the other end gateway will accept G.729 calls only with a payload of 30. By default the payload size for G.729 in Call Manager is 20, and this is the same used for their other internal VoIP calls.
If you want to change the payload, as far as I Know it has to be done under the Service parameters and will affect globally.
Because of this issue, we are not able to proceed with our integration. So please let me know if there is any way to change the payload type to 30 only for this particular trunk.