We have a frustrating issue where we intermittently have no audio on call pickup on incoming calls.
We have FreePBX on same LAN as 4 Grandstream GXP2160 phones.
Also have 1 Cisco SPA303.
Issue is present on all phones.
Can upload logs and traces if needed.
I’m guessing this is possibly an RTP issue, perhaps related to my NAT/Firewall settings.
Currently using a Mikrotik router with ports 5060, 10000-20000 allowed and forwarded to FreePBX on LAN IP 192.168.1.250.
Here is flow sequence of affected call from Wireshark.
Can give more info if needed.