WLAN controller redundancy over IP VPN

[Andre Liverod]

Customer currently has a Cisco 5500 WLAN controller at one of our datacenters. They want to add a WLAN controller as redundancy at their local site which shall be used as a secondary failover controller. This site is reachable over VPN. Which redundancy options do I have here? As i understand with HA functions the controllers has to be within the same L2 network and have low latency. Is my only option here to manually configure a new controller, buy double the AP licenses and copy the config from the old one? And if the first fail the APs would need to reboot and reassociate with the secondary controller?

Would be really greatful if someone could point me in the right direction

[George Stefanick]

You have a few options .. 

1. Buy two fully licensed controllers. One primary one secondary and configure as such.

2. HA N+1 where you buy one fully licensed controller and one HA controller or a controller with a minimum of 50 licenses. Put the secondary controller into ha mode and it will go to max licenses. 

http://www.cisco.com/c/en/us/td/docs/wireless/technology/hi_avail/N1_High_Availability_Deployment_Guide/Licensing.html

3. APSSO AND CLIENT SSO this is where you need layer 2. There is a data base that syncs between the

http://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/7-5/High_Availability_DG.pdf