You can configure the 802.11b/g/n (2.4 GHz) and 802.11a/n/ac (5 GHz) bands for the controller to comply with the regulatory requirements in your country. By default, both 802.11b/g/n and 802.11a/n/ac are enabled.
When a controller is configured to allow only 802.11g traffic, 802.11b client devices are able to successfully connect to an access point, but cannot pass traffic. When you configure the controller only for 802.11g traffic, you must mark 11g rates as mandatory.
The Block Acks in a Cisco 2800, 3800, 1560 APs are sent at configured mandatory data rates in controller for 2.4 GHz radio.
This section contains the following subsections: