Cisco BPX 8600 Series, Руководство по установке и настройке

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Glossary
15
Cisco BPX 8600 Series Installation and Configuration
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
N
n+1 redundancy A redundancy method in which a group of cards share the same standby redundant card.
Network-to-Networ
k Interface (NNI)
The protocol at a frame relay port that serves as a bidirectional interface between a local Cisco WAN
switching network and a separate and independent “other” network.
node An IGX or BPX switch serving as a connection point to the network. At a node, connections from
service lines are routed to trunks for transmission to other nodes in the network.
NPM (Network
Processor Module) Micro-processor based system controller front card that contains the software used to operate the IGX
switch.
Nrm
Maximum number of cells a source may send for each forward RM cell, that is, an RM cell must be
sent for every Nrm-1 data cells.
NTM (Network
Trunk Module) IGX front card that coordinates fastpacket trunk traffic to another node via a number of backcards:
T1, E1, Y1, and subrate (RS449, X.21, and V.35).
O
OC-3
Standard optical transmission facility rate of 155.20 Mbps.
OCC (Other
Common Carrier)
In the United States, reference to all the other telecommunications companies providing various
transmission services other than AT&T.
P
packet line Packet line referred to a line used to carry FastPackets between nodes in a network. The term in these
documents is replaced by the more general “trunk” which is defined as a physical link from node to
node, node to shelf, or node to network. The trunk may be one that supports 24-byte FastPackets
(packet trunk), or one that supports 53 byte ATM cells (cell trunk).
packet switching
A system that breaks data strings into small units (packets), then individually addresses and routes
them through the network.
PAD (Packet
Assembler/Disasse
mbler) A device that converts a serial data stream into discrete packets in the transmit direction and converts
the received packets back into a serial data stream. Adds header information in the transmit packet to
allow it to be routed to the proper destination.
partially-interleaved
EIA One control lead in each direction, generally RTS-CTS, is transmitted in same byte as seven data bits.
For fast control lead response to data being turned on and off.
PBX (private branch
exchange)
Digital or analog telephone switchboard, classified as customer premise equipment (CPE), used to
connect private and public telephone networks.
PCM (Pulse Code
Modulation) The system for transmitting telephone signals digitally. Voice is sampled 8000 times per second and
converted to an 8-bit digital word.
PCR (Peak Cell Rate) The maximum rate for an ATM connection at which cells are allowed into the network.