Public Switched Telephone Network (PSTN)

The Public Switched Telephone Network, or PSTN, refers to the globally interconnected public telephone network. It was originally developed for circuit-switched analogue voice communication and was subsequently expanded with digital transmission technologies. In traditional telephone communication, a dedicated communication path is established between participants for the duration of a call. The network includes switching systems, transmission lines, telephone connections and other telecommunications infrastructure. Internationally standardised telephone numbers are used to address individual subscribers. With the increasing adoption of Voice over IP, traditional circuit-switched infrastructures are being replaced or supplemented by IP-based telephone networks in many regions. Connections between VoIP systems and the public telephone network can be provided through VoIP gateways or corresponding service provider infrastructure.