Nortel Networks 1000M User Manual

Page 314

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314

Survivability

The outgoing-only, analog CO trunks are more cost-effective than
DID/DOD trunks.

Disadvantages:

Users of the IP Expansion Cabinets or Chassis cannot directly receive
incoming calls in survival mode.

Option 3: Multiple, public-exchange Listed Directory Numbers

Procedure 58

Configuring multiple, public-exchange Listed Directory Numbers (LDN) for
Survivability

Step

Action

1

Configure the Main Cabinet or Chassis with incoming and outgoing
CO trunks.

2

Configure the IP Expansion Cabinets or Chassis with incoming and
outgoing CO trunks.

3

Assign each cabinet or chassis a unique public LDN (referred to
here as LDN #0, LDN #1).

When an external caller dials LDN #0, the CO trunks on the Main
Cabinet or Chassis are accessed. When the external caller dials
LDN #1, the CO trunks on the first IP Expansion Cabinet or Chassis
are accessed.

In normal mode, all the CO trunks are used for both incoming and
outgoing calls. Unique LDNs are necessary to receive incoming
calls when the system goes into survival mode.

In survival mode, incoming calls to the Main Cabinet or Chassis
cannot be redirected to an IP Expansion Cabinet or Chassis. The
only way for an external caller to reach a user of an IP Expansion
Cabinet or Chassis is through the unique LDN of that cabinet or
chassis. When an external caller dials this LDN, the switch must be
configured to manually distribute the calls to the users on the cabinet
or chassis. These alternatives are described below.

Distributing calls to the users

a. Define one multiple appearance, Single Call Ringing (SCR) DN

on at least one telephone on each cabinet or chassis.

b. Assign this DN as the general Night DN for the system.

c. Assign these telephones to users who will answer and redirect

incoming calls in survival mode for each cabinet or chassis.

Nortel Communication Server 1000

Communication Server 1000M and Meridian 1 Small System Installation and Commissioning

NN43011-310

01.04

Standard

Release 5.0

13 May 2008

Copyright © 2008, Nortel Networks

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