Integrated Services Digital Network: ISDN is a circuit-switched telephone network system, designed to allow digital transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speeds than that available with the PSTN system.

Public Switched Telephone Network : PSTN is the world's collection of interconnected voice-oriented public telephone networks. It is a system based on copper wires carrying analog voice data

Please call AIRTEL on 1300 247 835, and see how Airtel can make your voice communication simpler and cost effective.