ATM Configuration and Troubleshooting Guide

Configuring EMS High Availability over ATM
Types of Failures Managed by EMS HA-ATM
Chapter 6100
Figure 6-3 below shows this configuration.
Figure 6-3 Configuration with Secondary LECS and ELAN
What Happens in Case of Failure In the configuration in Figure 6-3
above, if the primary ELAN fails, then the connections between all the
LECs and the primary LES/BUS are released. All the ELAN interfaces
then transfer to the secondary LES/BUS on the secondary ELAN. The
ELAN interface periodically attempts to re-establish contact with its
primary LES/BUS.
NOTE Although the ATM software allows you to configure only one LECS, we
do not recommend this, because a failure of the LECS will prevent
operation of the part of your ATM network that relies on that LECS.
ELAN interface
ELAN interface
ELAN interface
Primary LES/BUS
Primary LECS
Secondary LES/BUS
Secondary LECS
Primary ELAN
Secondary ELAN