Glossary

2B+D ◆ See BRI.

23B+D ◆ See PRI.

30B+D ◆ See PRI.

802.2IEEE ◆ Standards that govern the LLC within the Data Link layer of the OSI model. LLC frames carry user information between the nodes on a network and define the transmission of a frame between two stations. These standards are common across the various lower level standards within the Data Link and the Physical layers.

802.3IEEE ◆ Standards that govern the use of the CSMA/CD (Carrier Sense Multiple Access/Collision Detection) network access method used by Ethernet networks.

802.5IEEE ◆ Standards that govern the use of the token ring indicator and frame priority.

Adapter ◆ A device, usually a user interface card, that physically connects an end station to the network medium (for example, twisted pair, coaxial, fiber).

AIS (Alarm Indication Signal) ◆ PRI alarm, also known as Keep Alive or Blue signal. An unframed all-ones signal sent to maintain transmission continuity.

AMI (Alternate Mark Inversion) ◆ A method of digitally encoding data as electrical signals on a link.

ANSI (American National Standards Institute) ◆ An organization which coordinates, develops, and publishes standards used in the United States.

AT&T 5ESS ◆ The name of a central office switch manufactured by AT&T. These switches use Custom (proprietary) or National ISDN-1 (NI-1) software. ESS stands for Electronic Switching System.

Attenuation ◆ Signal power lost in a transmission medium as the signal travels from sender to receiver.

B8ZS (Bipolar with 8 Zeros Substitution) ◆ Α method of digitally encoding data on a link. A modified form of AMI used in the USA.

bandwidth ◆ Capacity for transmitting data through a given circuit. Generally, the greater the bandwidth, the more information can be sent through a circuit during a given amount of time.

iSPAN PRI PCI ISDN Users Guide

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