DX2xx are Nokia switch platforms.
DX200 is the same core NSS, but with mobile elements added on, BSC, HLR, VLR etc, . DX220 is the same core, but with fixed line elements added on, subs, ISDN, PRA etc.
But As I said, I wont be able to access my archive for four months.
I have had no reason to carry the info with me.
There used to be a chap called Alex who frequented this forum, but I havent seen his name for a while. He is very knowledgable. Maybe you sould search for his name.