[SR-Users] Re: Simultaneous INVITE responses from multiple branches

Hello, In our system we've encountered the following situation. There's a Kamailio proxy and a few REGISTER'ed devices behind the proxy. When there's an INVITE to these multiple devices, two of them simultaneously answer the call. Kamailio proxy accepts the first 200 OK from one of the devices and tries to CANCEL all other branches. But the second 200 OK device have already responded OK and doesn't acknowledge the CANCEL. So, there's now one established dialog with media, and another "established" one neither having media nor being correctly terminated. Looks like the similar scenario is described in section 3.1.2 of RFC 5407 (Example Call Flows of Race Conditions in the Session Initiation Protocol (SIP)). Is it possible to mitigate such scenarios in a Kamailio proxy? E.g., is it possible to send an additional BYE to these CANCEL'led branches? In current configuration, Kamailio proxy retrieves contacts with registrar:lookup() and does parallel forking with tm:t_relay().