Basic         +1 KX-NS520       +2 KX-NS520     +3 KX-NS520
Total Nbr of Lines             100         130               160            190
IP PHones                      64          64                64             64
SIP Phones                     64          64                64             64
Extensions                     162         194               226            258
IP Extensions                  128         128               128            128

Built-in Voice Mail
Built-In Outgoing Greeting Message (OGM)
Rack Mount type