Help Me with Policing configuration for 1G Link

[Ric Hernandez]

We're upgrading our 300Mb circuit with a full 1Gb circuit and I'm wondering what the recommended inbound policing percentages are for burst-normal and burst-max.

on the 300Mbps link we have:

    police 275000000 55000000 110000000 conform-action transmit  exceed-action transmit  violate-action drop

Is the recommended percentage 18% and 36% respectively or is there a formula for this?

[Georg Pauwen · Accepted solution]

Hello,

the formula is:

normal burst = configured rate * (1 byte)/(8 bits) * 1.5 seconds

extended burst = 2 * normal burst"

So in your case, the values would be:

police 275000000 51562500 103125000 conform-action transmit exceed-action transmit violate-action drop

which actually come very close to what you had originally configured.

[Ric Hernandez]

Thanks for your reply.  So for the 1G link I'm moving to, the numbers are as follows?

1,000,000,000 * 1 byte/8bits *1.5 ==> 187,500,000 and 375,000,000?

Any reason to put less than full rate of link in policing statement?

We currently have a 300Mb CIR on our existing link, but the policy was configured for 275,000,000

Our new circuit is a 1Gb link and I was going to put 910,000,000 instead of 1,000,000,000 on the policing statement, but is there a reason not to use 1,000,000,000?

[Joseph W. Doherty]

If your circuit's available bandwidth is full line rate, why are you policing?

[paul driver]

Hello

For a single rate -dual bucket- three colour policer

My understanding as follows:

BC = CIR/32
or
BC =CIR*0.25/8
Be=BC

so given that formula the above would be -

275mb
275000000 8593750 8593750 

or
281600000 8800000 8800000

1gb

1000000000 31250000 31250000
or

1024000000 32000000 32000000

Usually you would apply policing ingress, an example of this would be to police traffic ingress on you wan rtr for traffic originating from your Lan so as not to overwhelm  egress traffic on your wan connection.

res
Paul