Welcome! This site is devoted to sharing all kinds of information about ISDN. It was created by the North American ISDN Users' Forum (NIUF) ISDN Awareness Group and is operated by the National ISDN Council. Please feel free to contact us at m-isdn@notes.cc.telcordia.com.

ABOUT ISDN

Welcome to the world of Integrated Services Digital Network (ISDN). It's a switched, end-to-end network that allows for simultaneous transmission of voice, data, and video information. With two full duplex digital channels, Basic Rate Interface (BRI) ISDN provides high-speed connections for Internet access and other data applications. 128 kilobits per second(kbps) is typical, and up to 512kbps can be realized with data compression. BRI is the version most residences and small businesses use. Primary Rate Interface (PRI) ISDN bundles twenty-three channels together, to provide speeds of up to 1,544 kbps. PRI is the version most larger businesses use to network their geographically dispersed sites.

ISDN service is priced to provide good value for the residential and business user. With two 64 kbps B channels and a separate D channel for signaling, an ISDN Basic Rate connection is a more powerful telecommunications tool than two analog lines, yet is priced comparably in many cases. Furthermore, ISDN is competitively priced with other high-speed technologies such as Cable Modems.

ISDN is the only high-speed network that is widely available in North America, Europe, and the Pacific Rim. In the United States, ISDN is available almost everywhere. While new communications technologies such as 56K Modems, Cable Modems, and ADSL (Asymmetric Digital Subscriber Line) promise to emerge as alternative access methods into the data network, ISDN deployment continues to grow phenomenally, and with good reason. ISDN is a flexible 'high speed' service that is widely available today and supports current and emerging applications for data, voice, and video collaboration.

ISDN TIDBITS

ISDN (Integrated Services Digital Network) is a data service.

• It uses a digital telephone line to provide guaranteed, two-way bandwidth that's switched by the telephone network.
• Its Basic Rate service supports data capabilities like Internet access at speeds of up to 128 kbps (before compression).
• It supports packet operation to provide new capabilities like Always On/Dynamic ISDN - where the user can remain continually "connected" to the Internet without having a telephone call established.
• Other important ISDN data applications include Work At Home/Remote Access and Videoconferencing.

ISDN (Integrated Services Digital Network) is a voice service.

• ISDN supports digital voice calls to other ISDN and POTS (Plain Old Telephone Service) lines as well as a host of advanced voice capabilities (like Calling Number Delivery, Threeway Calling, Call Waiting, FAX transmission, etc.)
• ISDN Basic Rate can support two simultaneous voice calls on separate digital channels as well as multiple phone numbers.
• ISDN supports important small and large business services such as Key System operation and Centrex.

Best of all, ISDN Supports Voice and Data at the Same Time!