Hello all.. I'm a Nortel DMS 100-500 tech by trade. Well I'm trying to figure out how this Meridian is layed out. I hear the terms Option 11-81c, M1, CS1000. Can anyone tell me what the differance is between them? I have access to an Option 11 and trying to learn some of the basic commands on it.. It's nothing like a DMS or MSL. So please forgive my ignorance on this PBX.. Thank you for your time..