User's Guide

Table Of Contents
Availability and session availability
hwc_fastfailover.fm
Session availability
9034530-02, March 2010
394 HiPath Wireless Controller, Access Points and Convergence Software V7.11, User Guide
Session availability and topologies
Session availability applies only to the following topologies:
Bridge Traffic Locally at HWC
Bridge Traffic Locally at AP
Session availability is not available to users on conventional Routed VNSs.
Note: Session availability is not supported in a VNS that is configured for AAA
network assignment.
7.4.1 Events and actions in session availability
In the event of a primary HiPath Wireless Controller outage, or the network
connectivity failure to the primary controller, the Wireless AP:
Sends a ‘tunnel-active-req’ request message to the secondary HiPath
Wireless Controller.
The secondary HiPath Wireless Controller accepts the request by sending
the ‘tunnel-activate-response’ message.
The Wireless AP applies the backup configuration and starts sending the
data. The client devices’ authentication state is not preserved during failover.
When the fast failover takes place, a critical message is displayed in the
information log of the secondary HiPath Wireless Controller.
Note: In session availability, the maximum number of failover APs that the
secondary controller can accommodate is equal to the maximum number of APs
supported by the hardware platform and the license.
When the failed HiPath Wireless Controller recovers, each HiPath Wireless
Controller in the pair goes back to normal mode. They exchange information that
includes the latest lists of registered Wireless APs. The administrator must
release the Wireless APs manually on the second HiPath Wireless Controller, so
that they may re-register with their home HiPath Wireless Controller. Foreign APs
can now all be released at once by using the Foreign button on the Access
Approval screen to select all foreign APs, and then clicking Released.
To support the availability feature during a failover event, administrators need to
do the following: