D-Link DIR-68 User Manual page 41

Section  - Configuration
Enable QoS This option is disabled by default. Enable this option for better performance and experience with online games and other interactive
Engine: applications, such as VoIP.
Automatic
This option is enabled by default. This will allow your router to automatically determine the network priority of running programs.
Classification:
Dynamic
This option should be enabled when you have a slow Internet uplink. It helps to reduce the impact that large low priority network packets
Fragmentation:
can have on more urgent ones.
D-Link DIR-68 User Manual 41