[SR-Users] Detection of broken TCP connections to clients

Hi When clients register to Kamailio over TCP/TLS, if I set tcp_connection_lifetime to be quite small, like 30 seconds, and let clients send refreshes every 20 seconds, for example. When client crashes or have network problems, the TCP connection with Kamailio will be closed by the server after 30 seconds of being idle. My question is, is there a way of letting Kamailio tell which user the broken TCP connection belongs to, and then remove the user from the location table and update presence information etc? The reason I want this is, if a user publishes its status of being online with expiring time of 1 hour, but then crashed, then the location table entry and presence information of this user would be wrong for the rest of the hour. How do I get around this? I assume server can send periodic OPTION messages but that would be a bit expensive. Thank you very much! Yufei -- Yufei Tao Red Embedded This E-mail and any attachments hereto are strictly confidential and intended solely for the addressee. If you are not the intended addressee please notify the sender by return and delete the message. You must not disclose, forward or copy this E-mail or attachments to any third party without the prior consent of the sender. Red Embedded Design, Company Number 06688253 Registered in England: The Waterfront, Salts Mill Rd, Saltaire, BD17 7EZ