PABX – Telephony Solutions – Panasonic / Avaya
Short for Private Automated Branch Exchange, this telephone network is commonly used by call centers and other organizations. PABX allows a single access number to offer multiple lines to outside callers while providing a range of external lines to internal caller staff.
A business telephone system is any of a range of a multiline telephone systems typically used in business environments, encompassing systems ranging from small key systems to large scale private branch. A business telephone system differs from simply using a telephone with multiple lines in that the lines used are accessible from multiple telephones or “stations in the system, and that such a system often provides additional features related to call handling. Business telephone systems are often broadly classified into “key systems”, “hybrid systems”, and “private branch exchanges.
A key system was originally distinguished from a private branch exchange (PBX) in that it allowed the station user to see and control the calls directly, manually, using lighted line buttons, while a private branch exchange operated in a manner similar to the public telephone system, in that the calls were routed to the correct destination by being dialed directly. Technologically, private branch exchanges share lineage with central office telephone systems, and in larger or more complex systems, may rival a central office in capacity and features.
Hybrid Key Phone Systems
Into the 21st century, the distinction between key systems and PBX has become increasingly confusing. Early electronic key systems used dedicated handsets which displayed and allowed access to all connected PSTN lines and stations.
The modern key system now supports SIP, ISDN, analog handsets (in addition to its own proprietary handsets – usually digital as well as a raft of features more traditionally found on larger PBX systems. Their support for both analog and digital signaling, and of some PBX functionality gives rise to the “Hybrid” designation.
A hybrid system typically has some call appearance buttons that directly correspond to individual lines and/or stations, but may also support directly dialing to extensions or outside lines without selecting a line appearance.
The modern key system is usually fully digital (although analog variants persist) and some systems embrace VOIP. Indeed, key systems now can be considered to have left their humble roots and become small PBXs. Effectively, the aspects that distinguish a PBX from a hybrid key system are the amount, scope and complexity of the features and facilities offered.