Setup guide
Glossary
GL-2
Cisco 6400 Software Setup Guide
OL-1183-04
APS automatic protection switching. SONET switching mechanism that routes traffic from working lines to
protect them in case of a line card failure or fiber cut.
ATM
Asynchronous Transfer Mode. International standard for cell relay in which multiple service types
(such as voice, video, or data) are conveyed in fixed-length (53-byte) cells. Fixed-length cells allow
cell processing to occur in hardware, thereby reducing transit delays. ATM is used in high-speed
transmission media such as E3, SONET, and T3.
B
bandwidth The difference between the highest and lowest frequencies available for network signals. The term is
also used to describe the rated throughput capacity of a given network medium or protocol.
Bellcore Bell Communications Research, Inc., now known as Telcordia Technologies, Inc. Organization that
performs research and development on behalf of the RBOCs and sets telephony standards (in the United
States).
BER
bit error rate. Ratio of received bits that contain errors.
BITS Building Integrated Timing Supply. A single building master timing supply that supplies DS1 and DS0
level timing throughout an office.
boot flash Separate Flash memory device used primarily to store the Cisco IOS boot helper image, operational
Cisco IOS images, and system configuration information.
boot helper
Minimum-function Cisco IOS image that serves only to boot the full-function, operational Cisco IOS
image. Also referred to as “rxboot.”
BOOTP Bootstrap protocol. Protocol used by a network node to determine the IP address of its Ethernet
interfaces, so that network booting can proceed.
BPE Backplane Ethernet.
bps
bits per second.
bridge-group A group of interfaces bridged together to emulate a multiport bridge.
buffer Storage area used for handling data in transit. Buffers are used in internetworking to compensate for
differences in processing speed between network devices. Bursts of data can be stored in buffers until
they can be handled by slower processing devices. Sometimes referred to as a packet buffer.
BVI
Bridge Group Virtual Interface. The logical Layer 3-only interface associated with a bridge group when
IRB is configured.