Cause of Call timer start before call is answered

[DiDataITAAS]

We have a scenario here, call manager is connected to SIP trunk.

When a PSTN call is placed from a registered call manager extension, call connect timer starts before the remote party could answer the call.

This does not happen for local extension to extension calls.

What could be probable causes for this behaviour ?

Thanks,

[Mohammed al Baqari]

From CUCM can you share RTMT Real-Time Trace Tree for a call to see what is causing it.