Public Switched Telephone Network
PSTN is the oldest, slowest, and most common phone connection based on twisted-pair copper wires carrying analog data. This technology uses RJ-ll connectors. Computers require modems to convert digital signals from the computer to the anlog waveforms that travel across PSTN lines. PSTN phone lines take analog samples of sound 2400 times/second.
Shit man! PSTN sucks.