The 2 types of system (not including all the models) are the Strata DK and the Strata CIX. The DK is the older line and the 2000 series phones are the older phones that were used in the Strata DK systems.
I don't know the best way to determin what system is running your phone. I have heard mention here to try to dial with the phone onhook (hungup). If the phone does nothing then you would have the DK series phone system. If you can start dialing (hot dialpad) then you have the CIX system.
Somewhere there is a box on the wall that runs all the phones. In a house I would bet on it being a Strata DK40 or DK 16 (as mentioned above).
I have also seen them in garages, closets, and attics. It should be near the wiring, and it will be pluggrd into power.
