Glossary
GL-3
Cisco uBR7225VXR Universal Broadband Router Hardware Installation Guide
OL-17309-02
DSU Data Service Unit. Device used in digital transmission that adapts the physical interface on a DTE
device to a transmission facility such as T1 or E1. The DSUis also responsible for such functions as
signal timing. Often used with CSU, as in CSU/DSU.
DTE Data terminal equipment. Device at the user end of a user-network interface that serves as a data
source, destination, or both. DTE connects to a data network through a DCE device (for example, a
modem) and typically uses clocking signals generated by the DCE. DTE includes devices such as
computers, protocol translators, and multiplexers.
E
EIA Electronic Industries Alliance.
EMI Electromagnetic interference.
EPROM Erasable programmable read-only memory.
ESD Electrostatic discharge.
EuroDOCSIS European Data-over-Cable Service Interface Specifications.
F
Fast Ethernet Any of a number of 100-Mbps Ethernet specifications. Fast Ethernet offers a speed increase 10 times
that of the 10Base-T Ethernet specification, while preserving qualities such as frame format, MAC
mechanisms, and MTU. Existing 10Base-T applications and network management tools can be used
on Fast Ethernet networks. The Fast Ethernet specification is based on an extension to the IEEE 802.3
specification.
FEC Forward error correction.
Flash memory Nonvolatile storage that can be electrically erased and reprogrammed so that software images can be
stored, booted, and rewritten as necessary. Flash memory was developed by Intel and is licensed to
other semiconductor companies
FRU Field-replaceable unit. A component that can be removed from a network device and replaced in the
field. Line cards, power modules, and fan modules are typically FRUs.
G
GPS Global positioning system.
H
H.323 VoIP network Protocol that supports VoIP.