I have a customer who is using CCM 4.2 with transcoding resource on a C2800. The C2800 is also doing NAT for a SIP Trunk configured on CCM.
When we enable the Transcoding resource in CCM and try to make an IP Phone G729 call to SIP Trunk call G711 we get no media. I believe the problem is that the transcoding resource in the router is the source of the media traffic (rather than CCM MTP) and therefore its not being NATted.
Does anyone know what configuration would be required to enable the transcoding traffic generated locally on the router to be NATted to the addresses used by the SIP Trunk?