Cisco Router IOS XR Getting Started Manual page 208

Glossary
A routing algorithm determines that one route is better than another. This information is stored in
routing metric
routing tables. Metrics include bandwidth, communication cost, delay, hop count, load, MTU, path
cost, and reliability. Sometimes referred to simply as a metric. See also algorithm.
Protocol that accomplishes routing through the implementation of a specific routing algorithm.
routing protocol
Examples of routing protocols include BGP, OSPF, and IS-IS.
Table stored in a router or some other internetworking device that keeps track of routes to particular
routing table
network destinations and, in some cases, metrics associated with those routes.
route processor. Cards that contain run-control software on the router. Two RPs are installed as a
RP
redundant pair in dedicated slots in the front of each line card chassis.
Reverse Path Forwarding. Multicasting technique in which a multicast datagram is forwarded from all but
RPF
the receiving interface if the receiving interface is the one used to forward unicast datagrams to the source
of the multicast datagram.
Resource Reservation Protocol. Protocol that supports the reservation of resources across an IP
RSVP
network. Applications running on IP end systems can use RSVP to indicate to other nodes the nature
(bandwidth, jitter, maximum burst, and so on) of the packet streams they want to receive. RSVP
depends on IPv6. Also known as Resource Reservation Setup Protocol. See also IPv6.
The router configuration currently in effect. Although the user can save multiple versions of the router
running
configuration configuration for future reference, only one copy of the running configuration exists in the router at any
given time.
The receiver end of a fabric link. All links are unidirectional. See also Tx.
Rx
S
shelf controller/fan controller. Combines shelf controller function and fan controller function on one
SCFC
card. Two are installed in each fabric chassis.
Synchronous Digital Hierarchy. European standard that defines a set of rate and format standards that
SDH
are sent using optical signals over fiber. SDH is similar to SONET, with a basic SDH rate of
155.52 Mbps, designated at STM-1.
secure domain router. A collection of line cards and route processors that form a complete router. Each
SDR
router contains its own instance of dynamic routing, IP stack, system database, interface manager, and
event notification system.
synchronous dynamic random access memory. A form of dynamic RAM that adds a separate clock
SDRAM
signal to the control signals.
The hardware component that manages the configuration and health of a fabric chassis within the
shelf controller
Cisco CRS-1 router.
The shelf manager process runs on a router or switch, doing platform-dependent functions, including
shelf manager
handling OIR events. Shelf manager is formerly called platform manager.
Software Maintenance Upgrade. A "point fix" for a critical problem. SMUs are delivered as PIE files
SMU
and are used to update software packages.
Cisco IOS XR Getting Started Guide
GL-10
OL-10957-02