Hi, For now pjsip KA mechanism for UDP sig is to send keep alive packets only on the registration stream. When pjsip make an INVITE there is not such a mechanism for control channel. - At least I didn't found one ;) -. The problem is that some users reported me that with some NAT topology, the control channel gets cut as the NAT hole is closed. In consequence, the server or remote side is not able to send the BYE to the client. As far as I can understand from the code, this problem only affect UDP cause for TCP it is managed at transport level and KA should be sent regardless the kind of control channel it is. Is there some planned enhancement about that? Or is there another way to solve this problem? For reference the initial report on CSipSimple project : http://code.google.com/p/csipsimple/issues/detail?id=1347 Best regards, R?gis
