Hi Dany,
if i am correct you want to check the SIP messages being exchanged during the video call.
please follow the below steps:
1. take a ssh or telnet session of the codec using PUTTY.
2. make sure to enable all session output.
3. type the command: log output on
4. log ctx SipPacket debug 9
5. log ctx RTPStatistics debug 3
6. make call and recreate the issue.
7. hang up the call.
8. check the retreive logs for SIP messages being exchanged during the call.