afaik they all connect via 'ethernet' but I don't know what 'digital' is. Essentially, they all have a network cable that goes directly to a switch that connects them to the mitel box.
also, i will have to double check, (it's in another bldg a few miles away, and i wont be able to make it over there today since i have a doctors appt in an hour), but i think the people with computers have the network cable come into the phone, then a cable comes out of the phone and goes into the PC.
I don't think voice and data are on separate networks (the mitel server is 192.168.1.17 and computers are in similar ranges like 192.168.1.36) and I think our internet connection is therefor shared by both.
I'm going to place a call now to the ISP to find out what the deal is...