I have a branch office set up were all traffic goes back to the core, iincluding internet acces.
It has been working fine for a year, but recently I have started to see the firewalls Asa 5505 closing the connection and stopping the phone from answering the calls.
I have skinny inspection turned on all my branch offices, but had to turn it off at the one site to get one of my phones to registered.
I haven't made any changes to the network that would trigger this issue, such as upgrading phone firmware.
My firewall is configured for default deny, other than Skinny (tcp 2000), do I need Skinny inspection to be turned on?
It's turned on my 5 other branches.
How can I debug why the skinny inspection is closing the connection?
As a separate note this phone is part of a pool of phones that shares a common DN, would this be causing the issue?