Cisco Cisco IOS XE 3.5E Références techniques

HA with AP SSO is supported in Cisco 5700 Series Wireless Controllers. IOS XE 3.3 release only 
supports AP SSO i.e. APs will not disconnect and continue to be associated to the controller after a 
switchover. However, all clients will be de-authenticated and forced to rejoin new the Active WLC 
because Client SSO is not supported with this release.

A CT5760 HA Pair is a special case of a switch stack that can have up to two CT5760 controllers 
connected through their StackWise-480 ports. The stack members work together as a unified system. A 
third CT5760 cannot join the switch stack or HA pair.  A switch stack always has one active controller 
and one standby controller. If the active controller becomes unavailable, the standby assumes the role of 
the active, and continues to the keep the stack operational. The active controller controls the operation 
of the HA pair, and is the single point of stack-wide management. The term switch is loosely used in the 
document to refer to the CT5760 WLC for this reason.

StackWise-480 has a stack bandwidth of 480 Gbps and uses SSO to provide resiliency within the HA 
Pair. The Active CT5760 WLC creates and updates all the wireless information and constantly 
synchronizes that information with the standby controller. If the active WLC fails, the standby WLC 
assumes the role of the active WLC and continues to the keep the HA Pair operational. Access Points 
continue to remain connected during an active-to-standby switchover.

The StackWise-480 Cable is shown below and is available in lengths of 50 cm, 1 m, and 3 m.