VoIP Resource Library

A private, digital telephone system used by businesses to route calls through an internal network. Also referred to as an “on-premise PBX.” External lines may be integrated to allow for outbound calling.

A system similar to a PBX but managed virtually. The primary difference between an on-premise PBX and a virtual PBX is that, in the virtual model, a hosting company manages the hardware so businesses don’t have to purchase their own PBX servers.

VoIP refers to the interconnection all digital telecommunications properties, including servers and phones, that make communication possible across a global network. VoIP networks may operate entirely through the structure of the internet; they may also involve the PSTN to route calls to other homes and businesses.

The PSTN is composed of all transmission and switching facilities and signal processors supplied and operated by all telecommunications common carriers for use by the public. The most visible parts of the PSTN are the copper cables that run along telephone poles. The PSTN may also refer to fiber optic telephone lines, cellular networks, communications satellites, and undersea cables.

VoIP networks use digital packets to send information between devices, like between two users on a call. This is distinct from circuit switching, which formed the basis of traditional PSTN copper wire connections and required that a circuit remain active between users in order to establish and complete a transmission of information.