Nortel Networks SRG 50 NN43001-307 - Manual (Page 25)

Bandwidth Management Overview 25
The time zone of the SRG is configured with the SRG zone at the main
office. The time zone adjusts the main office time for display at the SRG.
SRG phones then display the correct time of the SRG, rather than that of
the main office. For any configurations using centralized Call Pilot on the
main office with one or more branch offices in separate time zones, the
NMS package is required at the main office for the branch IP Phones.
SRG IP Phone to local PSTN calls
When an SRG 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 SRG IP Phone.
The call is configured to be routed over the Virtual Trunk to the branch
office. The SRG then tandems the call to the local PSTN. Likewise, long
distance calls can also be configured.
If you use one Access Code for both local and long distance calls, and that
Access Code is associated with a branch office zone, all calls (local and
long distance) are routed through the SRG
IP Phone to analog (500/2500-type) telephone calls
When an IP Phone in Normal Mode at the SRG calls an analog
(500/2500-type) telephone of the same SRG, the call is processed at the
main office Call Server. A Virtual Trunk route is selected according to the
digits dialed. The call is routed over a Virtual Trunk to the branch office. The
SRG processes the incoming Virtual Trunk call and terminates it to the
local analog (500/2500-type) telephone. Since this is a call between IP and
circuit-switched devices, a DSP resource on a Media Card is allocated and
connected to the analog (500/2500-type) telephone. The IP address of the
DSP resource is returned to the main office Call Server so a direct media
path between the IP Phone and the DSP resource can be set up when the
call is established. See IP Peer Networking Installation and Commissioning
(NN43001-313) for details.
Conference calls
When an SRG user initiates a conference call, the conference facilities of
the main office are used. This means that in a conference among three
SRG users, the LAN/WAN bandwidth of three media paths is used. The
calls are controlled by the main office, except in Local Mode. In Local Mode,
SRG users do not have access to conferencing.
Networking consideration
A fault condition can occur if IP Phones use a different route to the main
office than that used by the SRG.
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
.