Keep Alive for 3CX SIP 5060

[spooner.arthur]

Hello,
I want to close incoming ports to the 3CX PBX to SIP 5060
Because it is not necessary, if the connections is open.
Now, I need to configure that OPNsense doesn't close the connection from the 3CX to the Provider.
How can I setup a keep alive for this?

Thanks, Regards
Arthur

[Monviech (Cedrik)]

When STUN is configured it will send keepalives to a STUN server to keep the port open.

[spooner.arthur]

I don't use STUN

If I disable the Rule SIP 5060 it works so long I have a Call.
But after some Minutes the OPNsense close the inactive connection.
I need to reregister the SIP Trunk on the 3CX

I hope there is a setting for Keep Alives

[Monviech (Cedrik)]

The OPNsense is not responsible for sending a keepalive.

The 3CX and the SIP registrar need to use keepalives, either with SIP Options or with STUN to keep the state of the stateful firewall open.