Understanding AutoQoS on the Cisco 9800 WLC
Enabling AutoQoS on a Cisco 9800 series WLC will allow you to use a set of predefined profiles to prioritise traffic flow. There are four types of AutoQoS that can be applied to a policy profile: Enterprise-AVC, FastLane, Guest, and Voice.
Each profile will apply a set of unique rules, setting the DSCP marking using different techniques depending on the direction of the traffic. The Guest profile will tag all traffic as best effort, whilst the Voice profile will ensure voice traffic is prioritized.
The BSSID Ingress and Egress profiles help correlate the DSCP tags to UP values. The below table represents the typical DSCP to UP value conversion:
The Access Point receives traffic from the client, the Wireless LAN Controller will use Application Visibility Control (AVC) to profile each application and set the relevant DSCP tag.
The Access Point sends the traffic to the client, the Wireless LAN Controller will match against existing DSCP tags, and re-tag the packets to ensure they are assigned to the correct UP queue.
The policy is applied to the interface and the traffic is assigned to a priority queue. Priority 1 is the highest priority, whilst Priority 2 is the lowest.