Hello, I have the following scenario: I receive an INVITE and do parallel forking, having two branches. What I would like to do then is set a timer for the first branch, and send a CANCEL on that branch in one of the following cases: 1. no final response is received on the first branch and the timer expires. In this case it is important that the timer is per branch, so not both branches expire, and not both are canceled. 2. a 181 Call is being forwarded reply is received on the second branch. Any suggestions are welcomed, because right now I have absolutely no idea how I could solve this. I read the documentation for the TM module, all kinds of timers, but they are all per transaction, not per branch, or at least so I understood. (I am using OpenSER 1.2) In conclusion, my questions are: 1. Can I set a per branch timer? (either from code or configuration script) 2. How can I send a CANCEL only on that branch when the timer expires? 3. How can I send a CANCEL on one branch when the other has received a non final reply, 181 in this case. (the problem is the actual generation and sending of the CANCEL message, not intercepting the 181 reply or finding out on which branch it was received). Thank you in advance, Madalina