Hello,

I am testing failover scenarios between two Active/Active kamailios for Sip over WebSockets and WebRTC.

In my test scenario, I have setup the call through proxy-a, then stopped the kamailio service so that the sip client reconnects to proxy-b. Dialogs and registrations are shared across both instances using MariaDB and Galera. When the SIP client reconnects to proxy-b, I send a BYE and see the following errors in the logs:

Jan 18 09:12:36 webrtc-proxy-b /usr/sbin/kamailio[6975]: ERROR: <script>: Connection ID: 1 Jan 18 09:12:36 webrtc-proxy-b /usr/sbin/kamailio[6975]: ERROR: <script>: WITHINDLG Jan 18 09:12:36 webrtc-proxy-b /usr/sbin/kamailio[6975]: ERROR: <script>: RELAY Jan 18 09:12:36 webrtc-proxy-b /usr/sbin/kamailio[6975]: WARNING: <core> [core/msg_translator.c:2765]: via_builder(): TCP/TLS connection (id: 0) for WebSocket could not be found Jan 18 09:12:36 webrtc-proxy-b /usr/sbin/kamailio[6975]: ERROR: <core> [core/msg_translator.c:1980]: build_req_buf_from_sip_req(): could not create Via header Jan 18 09:12:36 webrtc-proxy-b /usr/sbin/kamailio[6975]: ERROR: tm [t_fwd.c:476]: prepare_new_uac(): could not build request Jan 18 09:12:36 webrtc-proxy-b /usr/sbin/kamailio[6975]: ERROR: tm [t_fwd.c:1732]: t_forward_nonack(): failure to add branches Jan 18 09:12:36 webrtc-proxy-b /usr/sbin/kamailio[6975]: ERROR: sl [sl_funcs.c:362]: sl_reply_error(): stateless error reply used: No error (2/SL)

It seems that core/msg_translator.c is using the wrong WebSocket connection ID (0 rather than 1). Is this a bug in Kamailio or a limitation that I do not understand? I have assumed that the BYE is a new transaction for the existing dialog so t_relay() should be able to forward the message. I can provide config and any additional error logs if required.

Any help is much appreciated.

Thanks,

James