I have a guy I'm trying to help who has 7960 phones and is using some kind of SIP compliant app as the "call manager". He has the system working for the most part, but the important part does not...
What he's doing is, most of the calls he needs to originate egress through a voice gatway (5300...?) for toll bypass. This toll bypass is front-ended by an IVR system. When these calls are originated thus on a VOIP leg, they exit the 5300 on the WAN side g.711 and (obviously) they need to be g.729.
I _think_ this is because if it was a CCM, the conversation goes something like this:
1- The phone dials a call > ccm responds
2- CCM looks at the gatekeeper for the dial plan
3- CCM sees the foreign target address, picks up a ds0 on a T1 interface connected to the 5300
4- CCM siezes a DSP resource in the 5300 for transcoding, 5300 transcodes, tries to contact the foreign address
5- Call setup, call at specified codec
I think the process is going wrong at #4.
Can someone shed some light on a workaround?
