ISDN

Integrated Services Digital Network is a worldwide public standard for sending voice, video, data or packets over the PSTN in a digital format. There are 2 flavors - Basic Rate Interface (BRI) and Primary Rate Interface (PRI) - which we will learn more about this week. It is important to note that manufacturers implemented some forms of ISDN differently from each other. This resulted in some incompatibilities between ISDN in Europe, North America and Japan.

ISDN is used mainly in enterprise call centers, connections from businesses to local and long distance telephone companies, and videoconferencing. PRI and BRI ISDN use out-of-band signaling to carry dialed digits, caller identification, dial tone and other signals. ISDN works over existing copper wiring, fiber or satellite media.