Traffic policing comes with the following restrictions:
  • Does not support MAC classes.

  • Cannot configure burst size even though RFC 2698 allows you to specify committed burst size and peak burst size. Incorrect burst sizes can either lead to excessive traffic loss, or poor rate-limiting thus reducing the performance.

  • Cannot configure rates in packets-per-second.

  • Exceeded commit-rate packets are only DSCP remarked.

  • Operates only in color blind mode.

  • Applicable only for QoS policies and not PBR or mirror policies.

  • Cannot configure using Next Gen WEBUI or switch menu.

  • QoS policy containing a two rate meter can only be applied on individual physical interfaces, and not on logical interfaces (VLANs or LAG).

  • The Egress ACLs do not support DSCP remarking. As DSCP remarking is the only supported action for commit-rate violation, traffic policing cannot be enabled on an outward interface.
  • If you apply CoS through QoS ACL on the same port as two rate meter, the meter has a higher precedence over ACLs. The CoS value of the packet is set to zero as CIR/PIR DSCP is applied through a meter.