Can anyone explain PIM?

[nancy20]

I manage a call center which takes appointments for an eye care practice. The practice has 7 locations and our central scheduling dept handles all appointments & customer service. I've been with the company for just over a month. The vendor we use for our PBX has no info on paper for our phone system....it's all in his head. I had asked for a mapping of the calls etc...but no luck. The vendor is now suggesting we upgrade our phone systems. I can't get much info in "laymen's" terms as to what he's suggesting - hoping someone can explain. Our 7 locations operate independently of each other as far as our phone system is concerned. We can reach each other - but we need to upgrade for bettter connectivy etc. The suggestion was 1 cabinet (PIM) with intelligence....expandable to 240 ports. And IP phones/licenses. I really dont' understand this. I do understand IP phone technology & the potential for cost savings etc.

Can anyone offer any insight?

thanks.