Hello, not sure if I fully get the question. Are you saying the sequence is like this, for a connection over a TCP based protocol: INVITE 401 reply INVITE with auth, ACK, BYE REGISTER with Expires=0 401 reply No reply from client Then the TCP connection should be closed after the configured lifetime in Kamailio, default is 120s. You can tune this e.g. by setting TCP lifetime, keepalive and keepalive counter values as Kamailio core parameters. Cheers, Henning -- Henning Westerholt – https://skalatan.de/blog/ Kamailio services – https://gilawa.com *From:* sr-users <sr-users-bounces(a)lists.kamailio.org> *On Behalf Of *David Villasmil *Sent:* Saturday, November 12, 2022 4:39 PM *To:* Kamailio (SER) - Users Mailing List <sr-users(a)lists.kamailio.org> *Subject:* [SR-Users] Tcp/websocket closing Hello all, Question: Say there’s a client connecting via websocket, makes a call and then unregisters. But kamailio sends a 401 expecting the client to authenticate. If the client doesn’t, and simply stays there, at what point is the socket closed? Is it the OS timeout? Thanks! David -- Regards, David Villasmil email: david.villasmil.work(a)gmail.com phone: +34669448337