I am trying to connect a 3rd Party SIP Phone [Xlite] to CUCM 6.1 and make calls; the registration is successful, however when I try to generate calls I am getting resource allocation errors.
When I initiate a call, I get 100 Trying, 180 Ringing when the other party picks up, then I get 503 Service Unavailable.
When I analyzed the attached logs I found out, there is DTMF mismatch for which CUCM tries to allocate MTPs; however CUCM finds error in allocating MTPs.
MediaTerminationPointControl - ERROR AllocateMtpResourceReq failed
Can you please analyze the attached logs further and let me know what the root cause is.
PS- Other 3rd party SIP Phones [other than Xlite] work perfectly. Also Cisco IP Phone with SIP Firmware works perfectly.