What I think is happening:
- Extension 253 registered with an expiration of 60 minutes.
- The extension thinks it’s dropped and it tries to re-register, but the old registration is still “awake” from the previous session.
- The re-register fails because Asterisk thinks the old one is still active. The phone’s “new” registration fails so the phone doesn’t reconnect. Asterisk still thinks the old registration is active (since it hasn’t expired).
- 30 minutes later, the phone actually disconnects.
- 60 minutes later, the phone tries to reconnect and succeeds because Asterisk has deleted the registration.
As to solutions - try reducing all of the timeouts from hours to minutes or increase your number of contacts to 3. If you’re really concerned about the number of connections, you need find a more secure connection method. It’s dead simple for someone to take over one of your connections when no one is looking right now, so being concerned about setting the max contacts is just worrying about the wrong bad guy.
I understand that this should work the way you have it set up, but clearly that isn’t the case, so you’re going to have to jack around with the settings unless you can figure out if Bria or the network is causing the problem.