The ADTRAN NetVanta 7100 is a IP PBX and compares well versus the Cisco UC500, Avaya IP Office, Toshiba CIX, Shoretel, and other phone systems. Replace a hosted telephone solution with the NetVanta. What phone systems use Polycom phones? Many, including the NetVanta 7100. Use your old Polycom phones on a 7100 to eliminate the expensive hosted solution you have now. Reduce the cost of your hosted ip telephone solution by moving your phones to the NetVanta 7100.