I’m having problems with Cisco Phones going to an UNREACHABLE or LAGGED state. The phones are are behind a FIREWALL so are NATed. When I remove the “qualify” statement in the sip.cnf file, obviously, these statements disappear but everynow and then the phone will go directly to voicemail when called.
The phone will then not ring until it registers. I’ve reduced the register from 120, 100 and then 60. The phone consistently have this problem.
I’m at a loss at the moment and need to get these phones rolled out. Does any one have any idea what might be causing these problems?