Emergency Services Access 195
Determining the dialing plan for ESA calls
In many jurisdictions of the United States and Canada, the emergency
number must be “911”. The call processor cannot have a DN that conflicts
with these digits, but since “9” is often used forNARS AC2 (the local call
Access Code), this is not usually a problem.
ESA for international deployment must support the standard emergency
number 112 and any emergency numbers in use prior to the EU directive.
In general, ESA calls should leave the network through a trunk at the
branch office where the originating telephone is located. To enable this,
it is necessary for telephones at each branch office to supply a unique
identifying prefix to the NRS when the ESA calls are being routed so that
the NRS can select a distinct route for each branch office. This prefix can
be configured with the zone data for the SRG telephones. The provisioning
of this prefix is an enhancement for branch office.
While a variety of numbering schemes are available, Nortel recommends
that customers use 0 + the ESN location code of the SRG + ESDN, where
ESDN is:
for North America and CALA—911
for members of the European Union—112 and any other emergency
numbers in use prior to the EU directive
This number, referredto here as theESA Special Number, is configured as
a special number (SPN) in the NRS so that the Virtual Trunkroutes the call
to the branch office.
Use Element Manager or the Command Line Interface for the following
procedure. See IP Peer Networking Installation and Commissioning
(NN43001-313) for details.
Procedure 15
Configuring the main office
Step Action
1Configure the main office emergency trunk (CAMA or PRI).
Configure either analog CAMA or digital PRI to correctly signal the
call identification.
ESA overrides all restrictions. Configure the trunk with restrictions
so that other features cannot access the trunk.
2Configure the Virtual Trunk using the procedure from IP Peer
Networking Installation and Commissioning (NN43001-313).
Nortel Communication Server 1000
Main Office Configuration Guide forSRG 50
NN43001-307 02.02 Standard
Release 5.0 3 December 2007
Copyright© 2005-2007, Nor tel Networks
.