D-Link DSL-2740U User Manual page 70

Section 3 - Configuration
Enter the traffic class name, assign queuing priority and
optionally overwrite the IP header TOS byte. A rule consists of a
class name and at least one condition below. All of the specified
conditions in this classification rule must be satisfied for the rule
to take effect.
Click the Apply button to save and activate the rule
D-Link DSL-2740U User Manual 70