- 34 -

List of terms

connection-oriented routing (CO)

A routing service in which the path used by the frames or cells is determined when the connection is set up and remains fixed for the duration of the connection (barring network problems). Each path is set up on the nodes of that path and each packet needs a minimum of routing information.

connection preservation

The process of maintaining a connection over a sequence of potentially disruptive events such that the connection does not need to be reestablished when that sequence of events is complete.

Also known as call preservation.

constant bit rate (CBR)

An ATM Forum UNI 4.0 quality of service (QOS) class. This QOS class defines a static bandwidth that is continuously available for the duration of a connection. Corresponds to UNI 3.0/3.1 QOS class 1 and to Nortel Multiservice Switch constant bit rate QOS class.

Networks use CBR for voice, video, and telemetry services that need carefully metered transmission rates. In this sense, CBR emulates individual private line service. CBR avoids disagreeable “glitches” in service quality that result from data rate variance and data losses.

continuation of message cells (COM)

All cells in a stream between the beginning of message cell and the end of message cell, all of which belong to a series of cells that result from segmentation of higher-layer packets or frames.

control plane (C-plane)

Defines all aspects of the management and control of frame relay. The local management interface (LMI) is the interface to the C-plane. It uses procedures defined in

Frame Relay User-to-Network Interface With Extensions, document number 001-208966 (available through Nortel Networks)

ANSI T1.617 Annex D

ITU-T Q.933 Annex A

For more information, see NN10600-900 Nortel Multiservice Switch 7400/ 15000/20000 Frame Relay Technology Fundamentals.

Nortel Multiservice Switch 7400/15000/20000

Terminology

NN10600-005 7.2S1 Standard

PCR7.2 and up March 2006

Copyright © 2006, Nortel

Nortel Confidential

Page 34
Image 34
Panasonic 15000 Connection-oriented routing CO, Connection preservation, Constant bit rate CBR, Control plane C-plane