It is a private system in that it is typically used by one organization or one building complex. In telephony, an exchange is defined as a group of equipment controlling the connection of incoming and outgoing calls. Common control - PBX systems are controlled by one or more microprocessors operating under a stored program. Trunks can be incoming, outgoing, or a combination of both. User terminals - The user interface to a PBX system is the telephone set or voice terminal.
Nonvoice terminals connecting to PBXs include PCs and teletypewriters.
Recent PBX design has moved away from supporting standard single-line telephones in favor of proprietary electronic sets with enhanced capabilities. They are capable of moving telephone calls and faxes, along with data streams, over a single IP enterprise network. The systems includes call-routing software for Windows NT servers as well as an adapter to convert phones and fax machines into IP clients. For information and pricing on PBX products we offer from our GSA Schedule.