Capturing Call Answer event

Q. I am having difficulties in getting call answered event. Call Answered means when called party answers phone

I am monitoring a CUCM extension. Initially I used CiscoRTPOutputStartedEv event to signal answered event. It worked well with extensions which are in local CUCM.

When i called to local extensions, CiscoRTPOutputStartedEv got caught when call answered by called party. 

When I called to PSTN using CUCM extension, CiscoRTPOutputStartedEv event got captured when call was in ringing state.

When called party answerd call, CiscoRTPOutputStartedEv not captured by JTAPI.

 I used events like CallCtlTermConnTalkingEv,CallCtlConnEstablishedEv but unable to get any solution.

Am I using right approach to capture Call Answered event?

Is there another way to capture call answered event?