Nortel Networks SRG 50 NN43001-307 - Manual (Page 194)

194 Emergency Services configuration
Reregistering to minimally configured branch office
A branch user in Local Mode but who is not physically at the branch can get
incorrect emergency service handling.
If the SRG is not provisioned with knowledge of all the ERL in the enterprise,
one of two scenarios occurs when an IP Phone reregisters to the branch
(either by VO ESA redirection or by fallback to Local Mode):
• If the local TN is provisioned as Manual Update, then the phone inherits
the static location data. The static location data probably indicates basic
ESA processing (per LD 24) if this is a small branch.
• If the local TN is provisioned as Auto Update, then cached location data
in the phone is rejected if undefined locally, and unknown location values
(ERL = 0, ECL = 0, LocDesc = Unknown) are assigned. Unknown
location indicates default (basic) emergency processing (per LD 24),
which is acceptable for a small branch. A system message is also
generated to indicate that the phone location data was actually unknown
and defaults were used, but emergency calls should be handled
correctly.
Minimally configured branches (without LIS support) can be configured as
manual update.
Routing configuration for ESA calls on SRG 50
Use the following steps to configure routing for ESA calls for the SRG 50:
Step Action
1 Build a destination code corresponding to the ESA SPN for the
branch office.
2 Configure the destination code to absorb the leading digits for the
SPN, leaving just the ESDN.
3 Configure the destination code to use a public route to the PSTN
trunks.
4 Ensure the Remote access package (00 to 15 under Call Security)
assigned to the VoIP trunks has the appropriate Line Pool
Access/Bloc for PRI.
5 Ensure there is a Public Prefix of 911 with a length of 3 to match to
outgoing digits. This eliminates any delay. As soon as the 3 digits
are collected, the call is sent.
—End—
Nortel Communication Server 1000
Main Office Configuration Guide for SRG 50
NN43001-307 02.02 Standard
Release 5.0 3 December 2007
Copyright © 2005-2007, Nortel Networks
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