IBM 19K5716 manual Appendix C. a brief Isdn glossary

•Cold insertion/removal - Denotes the installation or removal of a peripheral device when the computer system is powered off and/or disconnected from the wall sockets.

•D channel - The second type of channel in ISDN BRI line. It carries 16 kbit/s and is mainly limited to signaling functions to control the B channels.

•D-channel switching protocol - Describes the telephone company's particular implementation of ISDN. The switching protocol is one of the key elements that determines whether a given ISDN adapter can be used in a given country. D channel switching protocols in use include:

—DSS1: Digital Subscriber System No. 1, commonly used in Europe where it is also called E-DSS1 or Euro ISDN

—NI-1: National ISDN 1, used in the United States of America and Canada

—5ESS: AT&T switching protocol, used in the United States of America and Canada

—G3 PBX Custom: AT&T switching protocol, used in the United States of America and Canada

—DMS-100 Custom: Nortel protocol, used in the United States of America and Canada

—NTT INS Net 64: NTT Docomo, used in Japan

—TPH 1962: obsolete D-channel switching protocol used in Australia; replaced by DSS1

—1TR6: obsolete D-channel switching protocol used in Germany; replaced by DSS1.

•DCE - Data communication equipment

•dpi - Dots per inch: a measurement unit for image resolution.

•DTE - Data terminal equipment

•E carrier system - E1 (or E-1) is a European digital transmission format devised by the ITU-TS and given its name by the Conference of European Postal and Telecommunication Administrations (CEPT). It is the European equivalent of the North American T carrier system format. E2 through E5 are carrier signals in increasing multiples of the E1 format..

The E1 signal format carries data at a rate of 2,048 Mbit/s and thus can carry 32 channels of 64 kbit/s each. E1 carries at a somewhat higher data rate than T1 (1.544 Mbit/s) because, unlike T1, it does not use bit-robbing, so that all eight bits per channel are used for signal encoding. E1 and T1 can be interconnected for international use.

The E1 signal format carries data at a rate of 2,048 Mbit/s and thus can carry 32 channels of 64 kbit/s each. E1 carries at a somewhat higher data rate than T1 (1.544 Mbit/s) because, unlike T1, it does not use bit-robbing, so that all eight bits per channel are used for signal encoding. E1 and T1 can be interconnected for international use.

•ETSI - European Telecommunications Standards Institute.

•Euro ISDN - The D-channel switching protocol adopted throughout Europe. In 1989, 18 telephone companies from different European states signed a

Appendix C. A brief ISDN glossary 225