GO HERE Incoming Calls Drop After Exactly 32 Seconds (Incredible PBX / FreePBX / Asterisk on Debian 12)

[pasuva]

My local Lan is in 192.168.1.0 (in fact my PBX is 192.168.1.14), Mi VPN server is in 10.8.0.0, the client (3cx softphone connects in 10.8.0.X in this case 10.8.0.6)

 

[pasuva]

Solved. It seems that the problem was MTU and packet latency, which caused packets to be lost. Changing the MTU and RTP Timeout has apparently solved the problem.

 

[seraj.sh]

Solved. It seems that the problem was MTU and packet latency, which caused packets to be lost. Changing the MTU and RTP Timeout has apparently solved the problem.

"Hello my friend, I have exactly the same issue you described here (Incoming Calls Drop After Exactly 32 Seconds). I have a MikroTik router, and my Issabel server is behind NAT. Any calls made between internal clients get disconnected after exactly 32 seconds. I have tried every possible solution I could think of, but nothing has worked so far. My internal extensions are of type PJSIP. How did you manage to resolve this issue?"

 

[wardmundy]

Google is your friend: https://share.gemini.google/ra0wiT1SJPvu

 

[Samot]

Google is your friend: https://share.gemini.google/ra0wiT1SJPvu

They have a PBX sitting behind a mikrotik router and the **internal clients** drop calls between them. There would be no NAT involved unless the network is really designed poorly. So unless all the traffic is hitting the router and the firewall is poorly designed then NAT and the firewall will not be involved. For example, if the PBX and the phones are all on the same switch then traffic never touches the router.

@seraj.sh You need to provide more details of the layout and structure. Is the PBX and the phones on the same network? Does internal traffic hit the router or is everything in a switch together?

 

[wardmundy]

SIP ALG is the typical suspect.

 

[Samot]

SIP ALG is the typical suspect.

Yes, only if the firewall is actually handling the traffic. Local traffic is typically not the case.