ADTRAN ISU 512 user manual NT1

Glossary

by multiple users. Typically, user data streams are interleaved on a bit or byte ba- sis (time division) or separated by different carrier frequencies (frequency divi- sion).

multipoint circuit

A circuit consisting of three or more stations connected directly electrically.

non-ISDN line

Any connection from a CPE to a SPCS that is not served by D-Channel signaling.

non-ISDN trunk

Any trunk not served by either SS7 or D-Channel signaling.

NT1

Network termination 1. A unit that provides physical and electromagnetic termi- nation of the U-interface 2-wire transmission line, converts between Layer 1 for- mats used at the U- and T- reference points, and performs some maintenance functions.

packet mode

Refers to switching of packets of information for different users by statistically multiplexing them over the same transmission facilities. ISDN packet mode capa- bilities are based on CCITT recommendation X.25 procedures.

point-to-point

Describing a circuit connecting two points directly with no intermediate process- ing nodes or computers (although switching facilities could exists). A type of con- nection that links two logical entities (i.e., phone-line circuit).

EIA-232-C

An EIA-specified physical interface with associated electrical signaling between DCE and DTE. The most commonly employed interface between computer devic- es and modems.

RS-366

An EIA interface standard for autodialing.

RS-530

Interface using a DB-25 connector, but for higher speeds than RS-232. Has bal- anced signals (like EIA-422) except for three maintenance signals which are EIA- 423.

SDLC

Synchronous data link control. A data communications line protocol associated with the IBM system network architecture. SDLC is a bit-oriented protocol (not a character-oriented protocol) that includes multiple block error checking and full duplex line operation.

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