I'm running a PAP2T behind a Linksys WAG200G, nothing fancy.
The last couple of days I've noticed that after a while if I pickup my phone I hear no dialtone, I've also had reports that people are calling and going straight to voicemail.
I checked the info screen on the PAP2T and it was showing as 'Online', I waited for a until it 're-registered' (message saying 'next registration in X seconds') and as soon as it did I had dialtone.
This happened a couple of other times, but I didn't login to the PAP2T to check - I assumed the re-registration would occur and the dialtone would return eventually but it didn't. Rebooting the PAP2T fixes the problem, but it returns a few minutes later.
I tried forwarding UDP 5060 + UDP 35xxx-37xxx (can't remember exact port numbers) but same result.
Perhaps the NAT/Firewall state table is not keeping the RTP session alive?
I used to have the PAP2T behind pfsense + Linksys AG241 and I forwarded UDP 35xxx-37xxx to the PAP2T to resolve one way audio issues, but I've since reverted to just using the WAG200G as the ADSL router.
Has anyone experienced similar issues?