Emergency 911 - Operator Control Of Disconnect; Overview; Location Information - Nortel 1120E Administration Manual

Emergency 911 - Operator control of
disconnect

Overview

For Emergency 911 services to be effective, it is vital that a system
maintains a connection with the 911 operator until the user provides
all necessary information. In traditional 911 telephony, if a 911 call is
disconnected before the necessary information is provided, mechanisms
are in place to allow the 911 operator to ring back the calling party. In VoIP
calls, 911 support is an evolving standard.
If the user of an IP Phone 1120E attempts to disconnect a 911 call after the
911 operator has answered, the IP Phone 1120E switches to hands-free
mode. Once the IP Phone 1120E is in hands-free mode, the 911 call can
only be disconnected by the operator.
Emergency 911 calls originate on the IP Phone 1120E and are completed
by the Call Server. The Call Server communicates with the 911 network or
911 systems for routing, call control, and location information. Although the
IP Phone 1120E allows users to enter location information, this location
information is not used by all Call Servers. Some Call Servers derive
the location information based on the number and location databases.
Characteristics of Emergency 911 calls and limitations of Emergency 911
calls using the IP Phone 1120E are given below.

Location information

Effective Emergency 911 services also rely on accurate location information.
The IP Phone 1120E supports the inclusion of the x-nt-location header in
SIP messages that provide location information to a Nortel call server. The
location information is selected by the user during registration, and must be
correctly provisioned at the call server level (see appropriate NTP specific
to your call server).
Copyright © 2008, Nortel Networks
.
SIP Firmware Release 1.1 for IP Phone 1120E Administration
NN43112-300 02.03 Standard
27 May 2008
99