Srg50 Operating Modes; Normal Mode - Nortel SRG50 Configuration Manual

SRG50 operating modes

The SRG50 has two operating modes: normal and local.

Normal mode

In normal mode
using VoIP trunks. From the perspective of the main office, the SRG50 is a branch office.
Figure 1 Normal mode
Branch office
IP phones
handsets
IP telephones connected at the SRG50 are registered with the main office call server and are under
main office control. They operate as branch user sets and have access to all telephony services and
features that the call server offers to IP telephones connected directly to the main office.
When a branch user set initiates a local PSTN call, the main office sets up the call using the VoIP
trunks, which establishes a local media path. Emergency Services Access calls are similarly routed
to the SRG50 PSTN. For main office callers, the SRG50 acts as a VoIP-PSTN gateway during
normal mode.
When call forwarding has been configured, incoming PSTN calls to the branch user set are
forwarded over VoIP trunks to the main office, which terminates the call at the branch user.
Similarly, calls from analog telephones connected to the SRG50 to the branch user set are
forwarded to the main office over VoIP trunks, which then terminates the call at the branch user.
Calls from the branch user set to the analog telephones at the SRG50 are routed over the VoIP
trunks to terminate at the analog telephone. In all these call scenarios, only signaling messages go
through the VoIP trunk. The media path is set up directly between the branch user set and the voice
gateway at the SRG50. This means that these calls do not use any WAN bandwidth between the
main office and the branch office after calls are established.
(Figure 1), the SRG50 is connected to the main office call server over a WAN
SRG50
WLAN
Software
phones
Survivable Remote Gateway 50 Configuration Guide
Chapter 1 Getting started
Main office
IP phones
VoIP connection over WAN
Normal mode
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