List of terms 215
Local ModeThe SRG is in Local Mode when:
•The IP Phones are first installed and not yet reregistered with the main
office
•The SRG cannot communicate with the main office andthe IP Phones
are reregistered with the SRG
•A user deliberately puts the IP Phone in the TestLocal Mode condition.
Main officeThe CS 1000 system that has been programmed to accept redirection of the
SRG IP Phones and provide call service for the SRG in Normal Mode.
NCS Network Connection Service. It provides a TPS interface to the NRS,
allowing the TPS to query the NRS using the UNIStim protocol. It is required
to support the main office, branch office, Virtual Office, and Geographic
Redundancy features.
Normal ModeThe SRG is in Normal Mode when the IP Phones on the SRG are correctly
redirected to the main office Call Server.
NRS Network Routing Service. The software application where all systems in the
network are registered. The NRS consists of the H.323 Gatekeeper and the
Network Connection Service (NCS).
PSTN Public Switched TelephoneNetwork. The international telephone system
based on copper wires carrying analog voice data. This is in contrast to
newer telephone networks based on digital technologies.
Telephoneservice carried bythe PSTN is often calledplain oldtelephone
service (POTS).
QoS Quality of Service, a networking term that specifies a guaranteed throughput
level. One of the biggest advantages of ATM over competing technologies,
such as Frame Relayand Fast Ethernet, is that ATM supports QoS levels.
This enables ATMproviders to guarantee to their customers that end-to-end
latency does not exceed a specified level.
There are several methods to provide QoS, as follows:
•high bandwidth
Nortel Communication Server 1000
Main Office Configuration Guide forSRG 50
NN43001-307 02.02 Standard
Release 5.0 3 December 2007
Copyright© 2005-2007, Nor tel Networks
.