Appendix H. Glossary - ADTRAN DSU III AR User Manual

Glossary
Appendix H
American National Standards Institute (ANSI)
Devices and proposes recommendations for international communications stan-
dards.
asynchronous
A method of data transmission which allows characters to be sent at irregular
intervals by preceding each character with a start bit, followed by a stop bit.
backward explicit congestion notification (BECN)
A bit set by a frame relay network to notify an interface device (DTE) that con-
gestion avoidance procedures should be initiated by the sending device.
bandwidth
The bandwidth determines the rate at which information can be sent through a
channel (the greater the bandwidth, the more information that can be sent in a
given amount of time).
bridge
A device that supports LAN-to-LAN communications. Bridges may be equipped
to provide frame relay support to the LAN devices they serve. A frame relay
capable bridge encapsulates LAN frames in frame relay frames and feeds them
to a frame relay switch for transmission across the network. A frame relay capa-
ble bridge also receives frame relay frames from the network, strips the frame
relay frame off each LAN frame, and passes the LAN frame on to the end device.
Bridges are generally used to connect LAN segments to other LAN segments or
to a WAN. They route traffic on the Level 2 LAN protocol (e.g. the Media Access
Control address), which occupies the lower sub-layer of the LAN OSI data link
layer. See also router.
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