Hi,

Can anyone clarify what the recommended burst vaules are for Class-Based Policing? The documentation for the rate-limit command suggests a normal burst of CIR [BPS] * (1 byte)/(8 bits) * 1.5 seconds and a extended burst of 2 * normal burst. For example:

rate-limit 1000000 187500 375000

The documentation for the police command is not as helpful and only provides the following example:

police 8000 1000 1000 conform-action transmit exceed-action set-qos-transmit 1 violate-action drop

If the burst size is not specified with Class-Based Policing the IOS defaults to a Bc of CIR/32 (250ms Tc) which is very different to the 1.5 seconds value Cisco recommends for the rate-limit command.

The documentation for the rate-limit command also states “Setting the extended burst value equal to the normal burst value excludes the extended burst capability.” I take it this is not the case with Class-Based Policing as the Cisco example has 1000 bytes for both normal and excess burst sizes?

If anyone can explain the differences between Class-Based Policing and Committed Access Rate burst values it would be appreciated.

Thanks,

Paul