PSTNverkosta
PSTNverkosta refers to the Public Switched Telephone Network (PSTN), the traditional public voice telephony system. In Finnish discussions it denotes voice calls and related services that originate from or terminate in the PSTN. The PSTN is a circuit-switched network that historically used copper telephone lines to carry analog voice, later digitized and transported over digital transmission links. It forms the backbone of fixed-line telephony in many countries and historically supported fax, modem data, and dial-up connections.
The PSTN is organized in layers. Local access networks connect customer premises to local exchanges, typically
Operation and services. A call is established through a dedicated circuit for its duration, providing predictable
Modern context. Many regions are transitioning toward IP-based voice (VoIP) and mobile networks, often introducing gateways