The public switched telephone network (PSTN) is the traditional worldwide voice telephone system, consisting of copper lines, fiber optic cables, microwave transmission links, and cellular networks. It relies on circuit switching to establish a dedicated channel between two endpoints for the duration of a call. While heavily digitized in the core, the edge of the network still supports analog devices and legacy dial-up equipment.
We need to keep one analog line tied to the PSTN just for the fire alarm panel.
Related terms
ISDN
Integrated Services Digital Network is an older standard for transmitting digital voice and data over standard telephone lines.
POTS
Plain old telephone service is the traditional analog voice transmission network using copper wires.
Telephone exchange
A central system of switches that routes calls between subscribers.
PBX
A private telephone network used within a company or organization.