Hi,
It happened again, I checked the captures and this is what is happening during the issue:
From KamailioB to KamailioC/D
1. Kamailio B is sending OPTIONS to KamailioC/D. 2. KamailioC/D are replying 200. 3. Kamailio B is not acting to those 200 and has the nodes DOWN (probably because it is in that "hung" state).
At the same time:
From KamailioC/D to KamailioB
1. KamailioC/D are sending OPTIONS to KamailioB. 2. KamailioB is NOT replying anything.
This time I had to restart Kamailio and it started working right away again.
[backtrace_20170701_2001.tar.gz](https://github.com/kamailio/kamailio/files/1117612/backtrace_20170701_2001.t...)
Sorry for so many posts, but I update this as things happen.