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Bandwidth Rate Limiting and QoS

This article relates to LoadMaster firmware version 7.2.53.

The LoadMaster's rate limiting and Quality of Service (QoS) capabilities have been enhanced to support bandwidth limiting at three levels:

  • Global: Across all clients accessing any Virtual Service

  • Client: For a single IP address or subnet accessing any Virtual Service

  • Virtual Service: For any client accessing a specific Virtual Service or SubVS

The global and client limits are available in the User Interface (UI) on the System Configuration > QoS/Limiting page, at the bottom of Global Limits and at the bottom of the Client Limiting section (which also contain the connection and request-based limiting that was released as part of LoadMaster firmware version 7.2.52). A bandwidth limit set at the global level overrides one set at either the client or Virtual Service/SubVS levels.

You can also set bandwidth limits at the Virtual Service and SubVS levels using a new control at the bottom of the Virtual Service and SubVS QoS/Limiting section. A bandwidth limit set at the Virtual Service level overrides one set at the SubVS level. Similarly, a bandwidth limit set at the global level overrides one set at the client, Virtual Service, or SubVS level.

In all cases, bandwidth limits are set in kilobits per second (Kbits/sec). The minimum setting is 16 and the maximum is 99999999.

Bandwidth limiting statistics are available in the UI on the Statistics > Real Time Statistics > Client Limits > Bandwidth page. The top 10 clients that have been dropped due to bandwidth limiting are displayed for the last 30 seconds, the last 5 minutes, and the last 30 minutes.

For further details on rate limiting in general, refer to the Rate Limiting Feature Description.