The Quality of Service field is available in the Standard Options section of the Virtual Service modify screen. To access this screen, in the LoadMaster Web User Interface (WUI) go to Virtual Services > View/Modify Services and click Modify on the relevant Virtual Service.
The Quality of Service drop-down sets a Differentiated Services Code Point (DSCP) in the IP header of packets that leave the Virtual Service. This means that the next device or service that deals with the packets will know how to treat and prioritise this traffic. Higher priority packets are sent from the LoadMaster before lower priority packets.
The different options are described below:
- Normal-Service: No special priority given to the traffic
- Minimize-Cost: Used when data needs to be transferred over a link that has a lower “cost”
- Maximize-Reliability: Used when data needs to travel to the destination over a reliable link and with little or no re-transmission
- Maximize-Throughput: Used when the volume of data transferred during an interval is important, even if the latency over the link is high
- Minimize-Delay: Used when the time required (latency) for the packet to reach the destination must be low. This option has the quickest queue of each of the Quality of Service choices.
Note: The Quality of Service feature only works with Layer 7 traffic. It does not work with Layer 4 traffic.