An engineer is planning an image upgrade of the WLC, and hundreds of APs are spread across remote sites with limited WAN bandwidth. The engineer must minimize the WAN utilization for this upgrade. Whi

Predownloading the image pushes it from the WLC to every AP individually before the maintenance window, so it still consumes WAN bandwidth proportional to the total number of remote APs rather than reducing it.

The Smart AP Image Upgrade feature assigns a master AP at each remote location that downloads the new image from the WLC a single time over the WAN; all remaining APs at that site then retrieve the image from the master AP across the local LAN. This ensures only one WAN transfer occurs per site regardless of how many APs are present, directly addressing the limited bandwidth constraint.

Allowing APs to download code after the WLC reboots is the default upgrade behavior and causes all APs to simultaneously pull the image from the WLC over the WAN, which maximizes rather than minimizes WAN utilization.

Parallel TFTP upgrades initiated via SSH is not a supported or standard mechanism for Cisco WLC-managed AP image distribution and does not address WAN bandwidth conservation at remote sites.