-If you're thinking about pursuing the Nortel Meridians, I personally would NEVER recommend any of those Meridian options to any technician as a first system to be exposed to. They require a very complex understanding and LOTS of experience!!
-As you begin to come in personal contact with experienced PBX installers, technicians, administrators, etc, always remember this: Any information that is shared with you from someone's direct experience is GOLD. Take good notes, and be a very open-minded, attentive, and focused "listener".
-Since the different manufacturers each have their own unique language/terminology/operating styles/etc for their PBXs, I'd recommend first learning and understanding basic concepts, standards, and features shared by all PBXs (different types of lines and trunks like Coral Tech mentioned, Direct Inward and Outward Dialing, the different standard & custom call features, types of call groups, RS/RJ/EIA connections & wiring standards, etc).
