Nortel Networks NN43001-314 - Manual (Page 166)

166 How the Branch Office feature works
Vacant Number Routing (VNR) is mandatory in a Branch Office. It enables
a Branch Office to route calls through the NRS, or other alternate routes if
configured, with minimal configuration. Instead of changing the numbering
trees and steering codes at each location, all the routing information can be
kept at one central location.
At the Branch Office, VNR is normally routed first to the Virtual Trunk. VNR
also enables Data Manipulation Index (DMI) numbers for all trunk types so
alternate routes can be configured.
If a vacant number is dialed, the number is not treated as invalid, and the
call is routed to the NRS. The NRS tries to determine where the terminal
is located. If the terminal is located, the call is routed to the terminating
location. If the terminal cannot be located, each of the alternate routes
are tried, in the configured sequence. If all alternate routes fail, the call is
blocked.
Time of Day
The idle clock on the telephone display must be localized to the correct time
for the geographic location of the IP Phone (the Call Server updates this
information on the telephone). The date and time display on the IP Phone is
determined by the Call Server to which the telephone connects.
The Branch Office feature allows branch offices to located in regions with
different time zone than the main office. The time zone of the Branch Office
is configured with the Branch Office zone at the main office. The time zone
adjusts the main office time for display at the Branch Office. Idle MG 1000B
telephones then display the correct time of the Branch Office, rather than
that of the main office.
MG 1000B IP Phone to local PSTN calls
When an MG 1000B IP Phone in Normal Mode dials a local PSTN number,
the call is processed by the main office Call Server. The dialed digits are
modified according to the dialing plan information configured in the zone
for the MG 1000B IP Phone.
The call is configured to be routed over the Virtual Trunk to the Branch
Office. The MG 1000B call server then tandems the call to the local PSTN.
This implementation can optionally be implemented for long-distance calls
over PSTN trunks.
Nortel Communication Server 1000
Branch Office Installation and Commissioning
NN43001-314 01.02 Standard
Release 5.0 20 June 2007
Copyright © 2007, Nortel Networks
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