NEC Univerge SV9100 Manual page 489

An added feature of NetLink is the Fail-Over feature. If the Primary System is turned off
or disconnected, without the Fail-Over feature, all communication servers would stop
working. With Fail-Over, the server locates one of the Secondary Systems as based on
the SV9100 programming, and it takes over the Primary System database allowing the
other linked nodes to continue functioning.
10-2
Figure 10-1 NetLink Fail-Over Example
Secondary
System 1
Primary
System
IP Network
Issue 2.0
Secondary
System 2
SV9100 NetLink