Nortel Networks NN43001-314 - Manual (Page 169)

Configuring non-zero S2 IP Addresses 169
When the telephone detects that it has lost communication with the main
office, it reboots and registers to the MG 1000B TPS. This means that,
depending on the network configuration (or the point of failure in the
network), not all MG 1000B IP Phones go into Local Mode at the same
time. Calls are not maintained during switchover from Normal Mode to
Local Mode.
IP Phones that are in Local Mode due to a network or main office failure are
automatically redirected to the main office when connectivity is restored.
Established calls are completed before the switchback from Local Mode
to Normal Mode.
To provide survivability for the IP Phones, the MG 1000B IP Phones must
be provisioned on both the Call Server at the main office and the MG 1000B
Call Server.
"Installing and configuring IP Phones" (page 264)
Configuring non-zero S2 IP Addresses
This section describes how to configure the S2 IP Address parameter on an
IP Phone at a Branch Office to provide additional survivability when:
• The MG 1000B TPS on the MG 1000B Signaling Server is not available.
Therefore, MG 1000B IP Phones cannot be redirected to the main office
TPS because the S2 parameter is set to NULL.
• The MG 1000B Call Server and any associated Voice Gateway Media
Cards in the MG 1000B Core are not available. Therefore, MG 1000B
IP Phones cannot be redirected to the main office TPS because the S2
parameter is set to NULL.
MG 1000B IP Phones register with the MG 1000B Call Server before being
redirected to the main office. If the sets cannot register with the MG 1000B
Call Server as described in the previous paragraph, they are not redirected
to the main office, even though the main office is fully functional and no
network problems exist between the Branch Office and main office.
Normally, an MG 1000B IP Phone registers with the main office TPS using
its S1 IP Address parameter. This section describes how an MG 1000B
IP Phone can register with the main office TPS using its S2 IP Address
parameter if one or more of the above events occur at the Branch Office.
Figure 64 "Configuration using S2 IP Address" (page 170) shows a typical
configuration using the S2 IP Address.
Nortel Communication Server 1000
Branch Office Installation and Commissioning
NN43001-314 01.02 Standard
Release 5.0 20 June 2007
Copyright © 2007, Nortel Networks
.