Glossary
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Cisco uBR10012 Universal Broadband Router Hardware Installation Guide
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PRE Performance routing engine. The central routing unit for the Cisco uBR10012 universal broadband
router. The PRE performs all Layer 2 and Layer 3 packet manipulation related to routing and
forwarding through the Cisco uBR10012 routers. Use dual PREs in a single chassis for redundancy. See
also PXF Network Processors.
PXF Network
Processors
Parallel eXpress Forwarding network processors. A pair of programmable ASICs that perform parallel
processing to support high performance Layer 3 forwarding.
Q
QoS Quality of service. A measure of performance for a transmission system that reflects its transmission
quality and service availability.
QPPB QoS Policy Propagation by BGP. A feature that classifies packets by IPprecedence based on BGP
community lists, BGP autonomous system paths, and access lists. After a packet is classified, other
quality of service features such as committed access rate (CAR) and Weighted Random Early Detection
(WRED) can specify and enforce policies to fit a business model.
Quality of Service See QoS.
R
RAM Random-access memory. Volatile memory that can be read and written by a microprocessor.
Random Access
Memory
See RAM.
Read only memory See ROM.
Redundancy In internetworking, the duplication of devices, services, or connections so that, in the event of a failure,
the redundant devices, services, or connections can perform the work of those that failed.
Remote monitoring See RMON.
Request for
comments
See RFC.
RFC Request for comments. A document series used as the primary means for communicating information
about the Internet. Some RFCs are designated by the IAB as Internet standards. Most RFCs document
protocol specifications such as Telnet and FTP, but some are humorous or historical. RFCs are available
online from numerous sources.
RMON Remote Monitoring. MIB agent specification described in RFC 1271 that defines functions for the
remote monitoring of networked devices. The RMON specification provides numerous monitoring,
problem detection, and reporting capabilities.
ROM Read only memory. Nonvolatile memory that can be read, but not written, by the microprocessor.