If you saw the wiring for this system, swinging jumpers wouldn't have been the easiest of solutions and it wouldn't have worked. System has 80 ports (around 70 sets across seven or eight buildings) but extension numbers ranged between 221 and 390 - obviously manually changed at some point.
The system did default during the upgrade so when it asked for the start DN, I entered 101. That way when I went to reprogram, I could say change 101 (which also matched the port number) to 221, 102 to 242, etc. Worked great for the first 32 ports and not bad for the three station modules
