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ISDN - Integrated Services Digital Network.
Full Definition
A CCITT standard for integrated transmission of voice, video and data. Bandwidths include: Basic Rate Interface - BR (144 Kbps - 2 B & 1 D channel) and Primary Rate - PRI (1.544 and 2.048 Mbps).
Integrated Services Digital Network. A set of protocol and interface standards that effectively constitute an integrated (voice, video, and data) telephone "network." These standards promote global availability and compatibility of ISDN products and services. The two types of ISDN discussed in this Guide are Basic Rate Interface (BRI) and Primate Rate Interface (PRI). ISDN BRI (ISDN Basic Rate Interface) is the interface to connect the desktop to the digital long distance network. ISDN BRI provides two 64Kbps B ("bearer") channels to carry information content, the voice, video, and data substance of a transmission. A separate 16Kbps D ("data") channel is used for call setup and signaling. ISDN BRI is often called "2B+D" ISDN, for its combination of two B and one D channel. This service is marketed and supported by the LECs. ISDN PRI (Primary Rate Interface) is the ISDN equivalent of a T-1 circuit. It provides 23B+D (in North America) or 30B+D (in Europe) running at 1.544 Mbps and 2.048Mps, respectively. Each channel (time slot) is 64Kbps. One channel is reserved as the D channel; the other 23, as bearer channels (23+D).
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