Table P-1: Evolution of PBX technology Generation Designation Nature of Technology 0 Cordboard Manual Switchboard 1 PBX Electro-Mechanical (Private Branch eXchange) Step-by-Step (SxS) 2 PABX Electro-Magnetic (Private Automatic Branch Crossbar (XBar) or Crossreed eXchange) 3 EPABX Electronic Common Control (ECC) (Electronic Private Automatic Analog or Digital Branch eXchange) Stored Program Control (SPC) 4 IP PBX or IPBX Digital (Internet Protocol Private Branch Stored Program Control (SPC) eXchange or Intranet Private LAN-based Branch eXchange) Voice over Internet Protocol (VoIP) 74570c16.qxd 9/11/07 12:27 PM Page 366 |