A Private Branch Exchange (PBX) is basically defined as a telephone exchange system or switching system within an organization that primarily provides intercommunication between the telephone stations in that organization. PBX switches calls between users of an enterprise on local lines to allow all the users share external phone lines. Private branch exchange ensures concentration of central office lines, which further helps in allowing two or more stations to establish conference calls or telephonic interactions between them without making use of central office equipment. Private branch exchange is not owned by telephone company or telecom service provider, but it is owned and operated by the enterprise itself.
A PBX includes:
· A network of communication lines within the PBX
· Telephone trunk lines or multiple phone lines which terminate at the PBX
· A computer system with efficient memory that can proficiently manage the switching or transferring of calls within the PBX
· A switchboard (or console) for a human operator; however, this is optional
Each PBX-connected station – a fax machine, telephone set, or even a computer modem – is generally referred to as “extension,” and each of these extensions is allocated an extension telephone number. These telephone numbers are usually not mapped to the numbering plan of central office or the telephone number block allocated to the private branch exchange.
The main purpose of using PBX system in call center outsourcing companies is to reduce the expenditures incurred on setting up a line for each user to the company’s central office. Using a PBX system, inbound call centers can handle circuit switching locally, and this helps immensely in minimizing the expenses related to telephone service via central-office lines. Initially Private branch exchange system gained immense popularity primarily because of its cost advantage. Later on, it started offering a wide range of feature services that were not available in conventional public network system, such as extension dialing, call forwarding, and line hunting.