Nortel 1000M Overview page 40

40 System architecture
Network organization
Network loops are organized into groups. A system is generally configured
as one of the following:
•
•
•
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:
•
•
•
•
Communication Server 1000M and Meridian 1 Large System Overview
Copyright © 2003-2008 Nortel Networks
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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
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
NN43021-110 02.05 Standard
30 September 2008