# Default QoS elements

There are three default QoS Classes: High Priority, Normal Priority, and Low Priority. These QoS Classes are used in the default QoS Policy, Prioritize.

The Prioritize QoS Policy is a sample policy that contains simple rules for prioritizing traffic according to the three default QoS Classes. High Priority traffic is assigned the highest possible priority value of 1. The Normal Priority value is 8, and Low Priority is assigned the lowest possible value of 16. The default Prioritize policy does not provide any bandwidth guarantees or limits.

CAUTION:
If you set priorities without setting any bandwidth limits or guarantees, high-priority traffic can use all available bandwidth, blocking all lower-priority traffic.

If the default Prioritize policy is sufficient for you, you can use the default QoS Classes and the Prioritize policy as they are. Add the QoS Classes to Access rules, then configure the interfaces to use the Prioritize QoS Policy.