There are a few different models of Cisco phones that the council uses. If you're asked what model your phone is, and you are unsure, check the back of the phone. There is a sticker with information about the phone, and on the second line it will list your phone model, e.g. CP-7821.
A quick rule of thumb is to check if your screen has colour. If it does, it's probably 8841. If not, it's probably 7821 or 7841.