Kamailio troubleshooting guides
The problems we get called out for most. Each guide covers what you'll see in the logs and SIP traces, the likely causes in order, and config that works on Kamailio 5.7 and 5.8.
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Kamailio problems we fix most often
Kamailio REGISTER stuck in a 401 Unauthorized loop
Phones retry REGISTER and Kamailio answers 401 every time. How to log why auth_check() fails, and fix realm, HA1, auth-user and nonce problems.
Read the fixOne-way audio through Kamailio and rtpengine
Call connects but only one side hears audio. Find the private IP in the SDP, fix rtpengine's advertised address, and engage it on every leg.
Read the fixKamailio dispatcher not failing over to the next destination
A gateway dies and calls hang for 30 seconds then fail instead of moving on. Enable dispatcher failover, a failure_route, short timers and probing.
Read the fixKamailio running out of shared memory (shm)
Kamailio logs shm allocation errors and stops handling calls. Size shm properly, find what's growing, and stop floods and stuck state eating it.
Read the fixKamailio TLS handshake failed
SIP over TLS won't connect: missing intermediate cert, wrong TLS version, client-cert checks or a renewed cert Kamailio never reloaded. How to fix each.
Read the fixWebRTC / SIP over WebSocket registration fails in Kamailio
JsSIP or SIP.js can't register through Kamailio over WSS. Fix the xhttp handshake route, tcp_accept_no_cl, Host checks, certificates and NAT handling.
Read the fixfriendly-scanner and SIP brute-force attacks hitting Kamailio
Stop SIP scanners and password guessing with Kamailio: drop known scanner user agents, rate-limit with pike, ban on repeated auth failures, feed fail2ban.
Read the fixKamailio won't start after upgrading from 5.7 to 5.8
Kamailio 5.8 fails with 'bad config file' after upgrading from 5.7. The real causes: archived modules, mixed packages, module paths and DB versions.
Read the fixKamailio MySQL errors: server has gone away, too many connections
Kamailio logs 'MySQL server has gone away' or 'Too many connections'. Fix idle timeouts, connection counts, blocking queries and auth plugin issues.
Read the fixKamailio in front of Asterisk or FreePBX: calls and registrations failing
Kamailio as the SIP edge for Asterisk or FreePBX: fix 'No matching endpoint found', calls not reaching phones, lost caller ID and one-way audio.
Read the fixGet a Kamailio engineer on it now
Emergency Kamailio support is £120/hour, 24/7. You talk to an engineer who has run Kamailio in production since 2005, not a ticket queue, and we'll sign your NDA before you send configs or traces. See pricing, or how our Kamailio support works.