SIP Troubleshooting: SIP Call Fail on SIP Trunk on Unified CM to Back to Back User Agent
MTP Resource Allocated Even Though MTP is Disabled
|Problem Summary||Media Transfer Protocol (MTP) Resource is allocated for each call coming into SIP trunk even though MTP disabled is selected on the trunk.|
|Possible Cause||Failure to negotiate DTMF method occurs for the call, according to the DTMF method supported by the endpoints involved in the call.|
|Recommended Action||Set the endpoints of the call to negotiate the same DTMF method, that is RFC2833 for Unified CVP calls.
Note: Out of Band (OOB) Key Press Markup Language (KPML) is not supported for the Unified CVP 4.0 and 4.1 releases.
|Associated CDETS #||None.|