How to configure Kemp LoadMaster quality of service(QOS) Options
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.
Comments
Added Differentiated Services Code Point values (Decimal) for each QoS option.
Only DSCP decimal 8 maps to a DSCP Class of CS1, These options are ToS not DSCP. I have added a feature request.
https://support.kemptechnologies.com/hc/en-us/community/posts/360004415472-DSCP-Qos-setting-on-Virtual-Servers
Changes reverted. Awaiting further clarification. Apologies for any confusion.
Systems Engineer
I have attempted to determine from support what DSCP code points are set for each of these options, and it appears that No corresponding DSCP code points match these settings