From denys.pozniak@gmail.com Thu Dec 8 10:28:39 2022 From: Denys Pozniak To: sr-users@lists.kamailio.org Subject: [SR-Users] Outgoing SIP/TLS connection error (msg_send_buffer(): tcp_send failed) Date: Thu, 08 Dec 2022 11:28:07 +0200 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0840129476==" --===============0840129476== Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Hello! We use trunk with Twilio through a SIP/TLS. They establish incoming calls from random ports, like: (Twilio)3.3.3.3:54321 --> (Kamailio)2.2.2.2:5061 In case of sending in-dialog requests to them, Kamailio should establish an outgoing connection to the dst port 5061 (as per Route), like: (Kamailio)2.2.2.2 --> (Twilio)3.3.3.3:5061 But as per tcpdump traces and logs, Kamailio does not even try to establish an outgoing connection to Twilio. There should be no problems with routes and the network on that server, as regular telnet to Twilio shows that 5061 is open. What could be the reason and how to debug? *Script:* onsend_route { xlog("L_ERR","[$cfg(route)]*RELAY ONSEND* $rm / $du / $fs / $fsn / [$ci]\n"); } *Syslog:* DEBUG [core/resolve.c:1259]: srv_sip_resolvehost(): 3.3.3.3:5061 proto=3 DEBUG [core/resolve.c:1371]: srv_sip_resolvehost(): returning 0x55acd63a63c0 (3.3.3.3:5061 proto=3) ERROR