I have a CounterPath X-lite sip softphone registered with our CUCM 6.1.4. The soft phone works great when calling within my location. I can call other SCCP phones and to our MCU audio conference bridge. However, when I call DNs in different locations over the WAN the call does not complete. X-lite dials fine and then the phone rings, but as soon as the remote end goes off-hook then the call is diconnected.
We have CUCM configured to use G729 across the WAN to different regions, but I would have thought that our SCCP phones would simply default back to G711 since X-lite only supports G711.
1) Where can I find logs in CUCM that might help me troublehoot (aka where the debug command)?
2) Any idea why this call doesn't go through?
Your assessment is the correct one. Because you have configured your inter-region voice CODEC to use G.729, the phones in the different regions will be unable to stand up the media stream. In other words, your calls are failing for the reasons you have already identified. If you go with the X-Lite pro, you can get the G.729 CODEC supported in the client and then you should be able complete your calls successfully. You only other alternative is to put X-Lite in a special device pool which has a special region that allows inter-region use of the G.711 CODEC.
Keep in mind that when CUCM refers to the audio CODEC they really mean the "best CODEC" not the "only CODEC supported". It is a subtle difference, but a difference nonetheless. It doesn't have an immediate impact on your scenario, but it is something to keep in mind. Also, with respect to SIP trunks, CUCM relies on the CODEC preferences in the SDP provided by the SIP-UA. Not sure how this plays with X-Lite as a client, but it may mean you will need to set a preference on CODEC choices. This assumes you decide to invest money into supporting the Counterpath product that you enjoy using and purchase the X-Lite pro.