Access Point Image download.

[Yuvaraj Gandhi]

Hi, 

Please help me with the Access point image download procedure. 

What is the maximum  bandwidth required for AP to download the image from controller?

thanks

[marce1000]

  - There are no bandwidth restrictions for AP image downloads from the controller. but usually on WAN links customers may for instance pre-download the AP image before upgrading a controller (e.g.)

 M.

[Rich R]

You have not specified what WLC or AP models you're using or the software version but generically speaking the slower the connection, the longer the download will take.  So a slow DSL line with high round trip delay will take much longer than an ethernet connected site.  There are some features designed to improve performance like Flexconnect AP Image Upgrade (1 AP downloads the image then the other APs download from the first AP locally) and in the latest versions of IOS-XE on 9800 called Efficient Image Upgrade with an additional enhancement called Out-of-Band AP Image Download to allow the AP to download the image over https instead of over the CAPWAP tunnel.
https://www.cisco.com/c/en/us/td/docs/wireless/controller/9800/17-12/config-guide/b_wl_17_12_cg/m_eff_image_upgrade_ewlc.html

You should also be aware of https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9800-series-wireless-controllers/220443-how-to-avoid-boot-loop-due-to-corrupted.html which affects some releases particularly with slower download links and MTU <1485.