I have a trunk without authentication.
I’m receiving PING Messages from my sip-provider every 60seconds. (They are confirmed by freepbx)
Then after some idle time (I’m trying to figure out if it’s a constant time) I’m no longer receiving ping-messages and a few minutes later I cannot place calls anymore.
After a failed call it takes a moment and I’m receiving PINGs again > and I can place calls.
Do you have any idea what it could be? I already contacted vodafone if they can see a something.
I’m using opnsense and a 1:1 NAT to a dedicated interface with a fixed public IP.