Lines all over the place.

Priority 1 calls: No names used, obviously. People here usually have reached a certain number of messages/contact frequency. 1 - Midnight in Moscow, 2 - Bluebird Story, 3 Chameleon, 4 - Where It Never Rains

Priority 2 calls: Current co-workers, those he often works with -- though they're likely to come and go and there may be huge stretches of time between: Concorde

Priority 3: Appointments, contacts, people he's working with (new or occasional colleagues), his message box, more urgent matters: From that dinosaur movie.

Those on his shit list, or calls that can wait, spam and other things: A single beep.