On 04 Feb 2014, at 15:43, Moritz Graf moritz.graf@g-fit.de wrote:
Shortly explained what RFC3578 is: In a open numbering plan you never know if the INVITE you received is already complete, or if there are more numbers coming in. One way of accomplishing this is to set up a timer. If the timer elapses you assume the number is complete. If not, you are receiving a new INVITE with one digit more. Now you have to close the old transaction with a "484 - Address Incomplete"-response and start the timer again. (Find the algorithm I want to implement attached)
You are not allowed to have two open INVITEs, the second one SHOULD get a 491 response. The client should not send a new INVITE if the old INVITE transaction is not complete.
I don't think overlap dialing in SIP was ever meant to be timer based. Consider that the first INVITE can go to a different proxy than the second. There's no dialog, no route set.
/O