When running a packet capture on the local network where my FreePBX resides, I notice a regular sequence of packets that involves RTCP and an destination port unreachable.
The hosts in the screenshot are
192.168.13.10 freepbx host
192.168.13.30 gigaset N300 that registers two DECT phones to sip accounts on the freepbox box.
The single remote IP is the sip trunk provider.
I see freepbx send RTCP Sender Report to both the N300 and the remote IP.
The external IP responds with ICMP port unreachable.
This pattern occurs at a regular interval whilst a call is in progress.
BTW whilst I have occassional disconnected calls, these appear to have no common patttern, particularly not in call length. So, whilst I hope to fix that, I don’t think this is related.
I would like to understand what is happening here with RTCP.
Many thanks