Cisco 5520 WLAN Controller Compatibility Issue

[FayasSalam95]

I am having  a Cisco 5520 WLAN Controller and 120 Access points associated with the same.My Controller is currently running software version of 8.2.141.0. Now i have to add Air AP 1815i into the same controller.For the same ,Do i have to upgrade my software version?How long it will cause me an outage?Is it recommended or else please suggest how to do the same?

[balaji.bandi · Accepted solution]

because of  Air AP 1815i i - you can not upgrade as you think, you need to think 120 device already connected, they compatable with new Code you looking to upgrade. if they yes.

each AP need to reboot and upgrade to latest firmware, so that means AP will go offline all connected user will disconnect and re-connect near any AP available to connect.

[Haydn Andrews]

As BB Said you will need to upgrade as the 1815i needs a minimum of 8.3.112.0.

You will need to confirm your existing APs are compatible with the version you go with, for this the Wireless compatibility matrix is helpful:

https://www.cisco.com/c/en/us/td/docs/wireless/compatibility/matrix/compatibility-matrix.html 

Suggest bookmarking it for future reference as well