Chapter 4 Failover Overview; Introduction - Nortel CallPilot Install Manual

Chapter 4
Failover overview
In this chapter
"Introduction" (page 33)
"Automatic failovers" (page 34)
"Manual failovers" (page 35)

Introduction

In a High Availability system, one server is active while the other is in
standby mode. If a failure occurs on the active server, the standby server
comes into service, becoming the active server. The process of the standby
server becoming the active server is called a failover.
The standby server takes over from the active server when:
•
•
In normal day-to-day use, end users are not aware that two CallPilot servers
are configured in a High Availability pair. There is one Control Directory
Number (CDN) configured on the switch that users call for any given
service. Any calls to a given CDN are routed to the CallPilot server that is
currently active.
If a failover occurs, the standby CallPilot server becomes the active server
of the pair and the switch routes incoming calls to the active server.
Copyright © 2007, Nortel Networks
.
A failure condition is detected on the active server and the software
triggers a failover to the standby server. This is known as an automatic
failover. For more information, see
A manual failover is initiated by an administrator to perform maintenance
activities, or when there is degradation of service that is not detected
by the AutoStart software. For more information, see
(page 35).
Note: The CDNs configured on both server must be the same.
Nortel CallPilot
High Availability: Installation and Configuration
NN44200-311 01.06 Standard
5.0 15 May 2007
"Automatic failovers" (page
"Manual failovers"
33
34).