ISDN

ISDN stands for Integrated Services Digital Network and is a type of dial-up connection that permits multiple digital channels to operate through a single network interface. ISDN comes in two types; BRI (Basic Rate Interface) and PRI (Primary Rate Interface). BRI uses two 64 Kbps channels for data and voice plus a 16 Kbps channel for control signaling and PRI uses twenty-three 64 Kbps channels for data and voice plus one 64 Kbps channel for control signaling. ISDN is a service provided by the telephone company (telco) and the connection can be brought up and taken down as needed. ISDN is often used as a back-up Internet connection to faster T1/E1 connections by businesses. If the primary T1/E1 goes down, the ISDN line can be brought up and business can continue until the main Internet connection is repaired.