[SR-Users] kamailio slow/no response for requests on particular ports

Hi, I have encountered an issue with kamailio and am hoping someone on this email distro can help: Here's my setup and description of the issue: I am running kamailio version 3.1.4. I have the kamailio process bound to ports 5060, 5070, and 5090. all UDP. I have several client devices registering to the kamailio registrar. The issue I have encountered is this: SIP registrations to port 5070 are fine for a period of time; by fine I mean clients send SIP registration requests to kamailio; and kamailio responds promptly to the request. by period of time I mean (this could be somewhat random) that for10 hours; 12 hours; 1 hour; that kamailo has no issue processing requests. after this random time period has elapsed, kamailo isn't able to respond to sip registrations and other messages in timely manner; to the point where the clients timeout and have to resend their registration requests. at times, kamailio does respond to the requests (with a significant delay) and at other times no response is received by the client. the user experience is intermittent registration delays/failures. The same behavior is seen on port 5090. I have not encountered the issue yet on port 5060. During times when kamailio isn't able to respond timely to requests on a particular port, requests to other ports are responded to timely. for ex: if port 5070 encounters the issue; port 5060 and 5090 seem fine. meaning, I can point my client devices to 5060 or 5090 and kamailio processes the requests timely. I have studied a tcp dump on the server end (kamailio side) and noticed that the network layer shows the messages from the client to be received timely while kamailio is encountering this issue. which indicates to me that it probably isn't a network lag related issue. Something at the application layer is probably causing kamailio to not respond timely. Furthermore the issue resolves itself after a period of time; that is, kamailio begins to respond to messages timely on the problematic port. I haven't had a chance yet to determine exactly how long it takes to recover. it certainly takes some time though. at least 30 minutes; maybe more. I can also state that the load on the kamailio system is minimal. far below than what the performance metrics state it can handle. Has anyone encountered this issue where kamalio isn't responding to registration and other requests timely on a particular port but does so fine for other ports? Any help on this would be appreciated. Thanks, Karthik