Nortel Networks NN43021-110 manual Network organization

40System architecture

Network organization

Network loops are organized into groups. A system is generally configured as one of the following:

•a half group system (CS 1000M HG) that provides up to 16 loops

•a single group system (CS 1000M SG) that provides up to 32 loops

•a multi-group system (CS 1000M MG) that provides up to 256 loops

The Fiber Junctor Interface (FIJI) cards in the Network modules are connected with fiber-optic cables to form a Dual Ring Fiber Network. This network consists of two separate rings: one ring connects all the Network shelf 0s while the second ring connects all the Network shelf 1s. This network communicates on a subset of the Sonet OC12c protocol (622 MB bandwidth on each ring).

The Dual Ring fiber-optic cable configuration provides complete non-blocking communication between the Network groups; this eliminates the incidence of busy signals for calls switched between groups. Each FIJI card can handle 32 PCM links. A system of eight Network groups provides 8000 timeslots for 4000 simultaneous conversations.

This Dual Ring network is fully redundant: each of the fiber-optic cable rings is capable of handling the traffic for an entire eight group network. If a fault in one ring is detected, the other ring automatically takes over call processing. No calls are lost during the switchover.

The Dual Ring Fiber network operated under four states:

•Normal

—Traffic is shared between the two rings.

—Each FIJI card drives 480 timeslots.

•Full

—Traffic is handled by a single ring.

—Each FIJI card drives 960 timeslots

•Survival

—FIJI cards in both rings are used to maintain intergroup traffic.

•Disabled

—The ring is inactive and does not support call processing.

Nortel Communication Server 1000

Communication Server 1000M and Meridian 1 Large System Overview

NN43021-110 02.05 Standard

30 September 2008

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