Incoming and outgoing calls have been working fine for me (near Pentagon), though I haven't received incoming from outside local area that often.

After bad calls that don't go away with ATA reset, I'd open a ticket and give them the call reference id listed on the call log.

(unrelated but curiously, my RT31P2 has always been registered on Central 174.37.45.134 and not East 208.43.68.151)