Cisco BPX 8600 Series, Руководство по установке и настройке

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Glossary
6
Cisco BPX 8600 Series Installation and Configuration
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
CLLM
Consolidated Link Layer Management. A protocol used to transmit ForeSight messages across the
frame relay NNI port.
CLP (Cell loss
priority)
Cell loss Priority. CLP Hi and CLP Lo thresholds are configurable.
Complex Gateway
Refers to interworking of a connection with respect to the IGX nodes. For example, in a Frame Relay
to ATM interworking, the Frame Relay data is extracted from FastPackets and transformed to ATM
cells with redundant overhead bits discarded.
composite data
rate
The sum of the data rates for all circuits transmitting on the same synchronous or frame relay data card.
control port An RS-232 port on the face plate of a back card for a controller card (BCC, NPC, NPM.) that may used
for connecting a control terminal. This port is bi-directional.
COS (Class of
Service) The priority assigned each user connection. Defines which circuits get rerouted first during a network
failure.
COS Buffer
A buffer or queue that serves connections with similar QoS requirements. Also called “qbin” (though a
qbin is a platform-specific instance, such as a BXM card, of the more general Class of Service Buffer
(CoSB).
Class of Service
(CoS) Buffer
Descriptor
Template A component of a Service Class Template that contains Class of Service Buffer configurations indexed by
CoSB number.
A qbin is a platform-specific (BXM in this case) instance of the more general Class of Service Buffer (or
CosB).
CLI There are two separate Command-Line Interfaces on the BPX-LSR: One on the BPX itself and one on the
MPLS (Multiprotocol Label Switching) Controller. The Control Point integrate these into a single command
line interface.
CommBus
The CommBus is the BPX’s internal messaging protocol. The Switch Control Interface (SCI) that is used
by PNNI on the Service Expansion Shelf (SES) is based on CommBus messaging accessed through
interfaces to the BPX cards.
CoSB See Class of Service (CoS) Buffer.
courtesy downing A software feature that is used to conserve network bandwidth by automatically “downing” a voice
connection when the signalling status indicates an inactive (on-hook) circuit. The circuit is
automatically “upped” when the circuit becomes active.
CRC (Cyclical
Redundancy Check)
A method of error checking that detects errors in a block of data. Unlike parity checks, the CRC can
detect multiple data errors within the block and thus equipment using a CRC error check can derive a
error rate.
crosspoint switch A two-dimensional data switch type that is arranged in a matrix of all input connections along one axis
and all output connections along the other axis. Each input and output line has a switch point where the
two axis intersect that can be enabled (switch closed) or disabled (switch open). The central matrix
switch providing the switching matrix for traffic routing by the BPX switch.
CSU (Channel
Service Unit) A network protection unit that terminates any T1 span line connected to the carrier's central office,
providing receive direction regeneration and maintenance loopback for the 1.544 Mbps signal.
C