Nortel 1000 Configuration Manual page 203

In many jurisdictions, the emergency number is a fixed number (for example,
112 or 999). The main office Call Server or SRG cannot have a DN that
conflicts with these digits.
Access to Emergency Service using SPN should be configured in the
following circumstances:
•
•
•
To configure Emergency Service using SPN, follow the process outlined in
"Dialing Plan configuration" (page
configured, Emergency Service from the branch office will already be
present.
Branch office access to Emergency Service using SPN must be configured
and tested the main office Call Server and the SRG to differentiate between
emergency calls originating from IP Phones at each location and emergency
calls originating on trunks.
The special handling provided by ESA is not available in this scenario, such
as OSN and zone-based routing.
For information on emergency services for Virtual Office, see Emergency
Services Access Fundamentals (NN43001-613).
Copyright © 2005-2007, Nortel Networks
.
When the Emergency Service number at the branch office is different
from that at the main office.
When there is more than one number used for accessing Emergency
Service; for example, when there are different numbers for Police, Fire,
and Ambulance services.
In markets where the ESA feature is not available (outside of North
America, CALA, and EMEA).
Nortel Communication Server 1000
Main Office Configuration Guide for SRG 50
NN43001-307 02.02 Standard
Release 5.0 3 December 2007
Emergency Service using Special Numbers (SPN) 203
43). If SRG PSTN access is correctly