On 10/19/12 11:16, Juha Heinanen wrote:
i have not see in any document description about how long rtp proxy keeps the call state after it has received US command, but no matching LS command. is there a timer that clears those hanging calls once in a while and sip proxy config writer does not need to care about them. could the hanging calls offer a DoS attack possibility?
There's two timeouts, configurable through command line options, one is for active calls and defaults to 60 seconds, the other one is for silenced and not fully established calls and defaults to 1 hour. Calls will be cleared if no RTP traffic nor any re-invite has been detected for this amount of time.
if the change that you propose is made, then consider the setup where two UAS are both behind nat and one replies with 480. if rtp session of that leg is deleted without to tag, would it also delete the other rtp session to which no reply has not arrived yet?
Yes it would, which is one of those undesired side effects that I mentioned :) and it's probably why the current implementation behaves the way it does, and it's also why those cases should really be handled on SIP proxy side.
cheers