You can use QoS lists to change the DSCP and Ethernet IEEE 802.1p CoS fields in packets. Changing these fields adjusts the priority of packets meeting the criteria of the QoS list. DSCP values are mapped to a CoS value. Rules can be created determining the priority behavior of either individual DSCP values or CoS values, and can be based on specific values or groups of IP addresses, protocols, ports, IP fragments, or DSCP values. When a packet matches a rule on the QoS list, the Branch Gateway sets one or both of the QoS fields in the packet. See Allowed values on QoS fields.

Each QoS list also includes a DSCP table. The DSCP table enables you to set one or both of the QoS fields in a packet, based on the previous value of the DSCP field in the packet.