Mist AI access points can support up to 15 SSIDs per radio. Each SSID enabled on an access point radio will result in a beacon management frame being transmitted every 102.4ms. So as an, example, 5 SSIDs enabled on the same radio would result in 5 beacon frames being transmitted by the access point every 102.4ms. Although they are necessary, beacon frames are considered to be overhead as they consume valuable airtime. The maximum number of SSIDs which should be enabled on each AP radio will depend upon the data rate at which beacon frame are transmitted and co-channel contention levels. Beacon frames will be transmitted at the Minimum Basic Rate (MBR). Mist recommends keeping the number of SSIDs assigned to each radio to a minimum. Below are some guidelines for the number of SSIDs which can applied for different data rate settings in the Mist UI.