Most people in the department have CellPhones, so info on campus phones has become less important. Still it may be nice to know.
The area code for the campus and the UTC area is 858. Most campus phones are in the 534, 533, or 822 exchanges (ie of the form 534-XXXX). If you're calling from an on campus phone, you only need to dial the last 5 digits (ie 4XXXX). To dial off campus dial 8 first. You will need a special access number, access to some privileged phones, or a calling card to dial long distance. The department asks that you are reasonable with your calls, as they have to pay for some local calls. Most labs have phones paid for by the sponsoring faculty.