Nortel Networks NN43001-314 - Manual (Page 174)

174 How the Branch Office feature works
With all sites using the same ESDN, a conflict occurs in the NRS. The
conflict is resolved by using a unique prefix for each site, which the main
office adds as it routes the call. The suggested prefix is the ESN home
location code of the MG 1000B CP PM, or alternately, the Number Plan
Area (NPA) code of the MG 1000B CP PM if there is not more than one
Call Server in the NPA. Virtually any unique string can be used as a prefix
because the call is sent to the NRS as an SPN. In the NRS, SPNs have
their own separate numbering plan.
The Automatic Number Identification (ANI) data sent to the Public Safety
Answering Point (PSAP) identifies the location of the caller. In some
constituencies, legislation requires one DID per fixed number of square
feet, so the physical location of the emergency can be approximated based
on the telephone number delivered to the PSAP. The ESA feature has a
comprehensive scheme that can be used to convert an extension into an
appropriate DID.
If the Branch Office is relatively small, it can be easier to use a single, fixed
DID number for the Branch Office. This can be configured using the CHG
ZESA command in LD 117, where the <ESALocator> parameter is the DID
telephone number to be sent for use by the PSAP to locate the source of the
emergency call. For more information on this command, refer to Software
Input Output Reference - Maintenance (NN43001-711).
Configuring SPN for emergency services
Using an SPN for access to emergency services uses the digit manipulation
capabilities configured for the MG 1000B zone as follows:
• If the Branch User is in Normal Mode, the user dials the Access Code
for the local PSTN and the normal DN for emergency services.
If the main office and Branch Office use the same DN for accessing
emergency services, a conflict occurs in the NRS. The conflict is
resolved by using the Zone Dialing Plan (ZDP) configured in the Branch
Office. The digits specified by the ZDP are prefixed to the dialed digits,
and the call is then sent to the NRS as an SPN. In the NRS, the SPNs
have their own separate numbering plan. The call is routed to the MG
1000B Call Server so that it can be sent out to the MG 1000B PSTN.
• If the Branch User is in Local Mode (or an analog [500/2500-type] or
digital telephone at the MG 1000B), the user dials the Access Code for
the local PSTN and the normal DN for emergency services access. This
selects the appropriate trunk for local PSTN access.
Abbreviated Dialing
With the Abbreviated Dialing feature, users in the same geographic location
(the Main Office or the Branch Office) can call one another with a DN
shorter than the configured DN.
Nortel Communication Server 1000
Branch Office Installation and Commissioning
NN43001-314 01.02 Standard
Release 5.0 20 June 2007
Copyright © 2007, Nortel Networks
.