Drop Connection

[emmetre]

Hi, i have problem with 3cx 15.5 and voip provider Cheapnet (IT)

After a while i can't receive call

Here reply of provider
Hello we do not see our servers falling out of our servers, calling your number, we see the routed call to line xxxxxx to IP xxxxxx to the UDP port 61816 from which your 3CXPhoneSystem is being recorded. But by performing the tests we do not receive the answer as if our INVITE SIP package did not reach your switchboard. On your 3CX log of incoming call logs? It might be the router that provides connectivity that after a certain period of time does not recognize our INVITE SIP packets as allowed, may have been incorrect port forwarding rules enabled on the router itself the new 3CX switchboard.

I need to open port 61816?
Thanks

 

[lneblett]

Were the details in their reply of "xxxxxx to IP xxxxxx " correct?
You can and should use the built-in capture function of 3CX to make a call and then, if possible, of an inbound call. The outbound call capture will show how 3CX is constructing the message and if this appears correct, then it may be your router configuration. I assume you first ran the firewall checker and it passed?

 

[NickD_3CX]

If you haven't changed the default SIP Port of your 3CX, it should be 5060. This means that your Provider should see the traffic coming from your Public IP from UDP 5060. By the time they are stating that they see the traffic coming from 61816, then your Firewall might be doing some sort of source port remapping.

A good way to check this is to run the Firewall Check test from the Dashboard. If it fails, you must adjust your firewall accordingly. If you need the technical explanation about what the Firewall Check test does, you can find the information here: https://www.3cx.com/docs/firewall-checker/