Policy-map / not reaching the required band

[Ahmed Erfan Mehdi]

Dear Friends,

We have set below policy as below:

Policy Map xxxxxxx

    Class class-default

     police cir 4354000000 bc 136062500

       conform-action transmit

       exceed-action drop

bc value is auto and our customer cant reach more that 4330 Mbps, if i remove the policy , he can reach 4600 Mbps.

Please advise.

Regards,

Ahmed

[nkarpysh]

Hello,

You need to tune the Bc. Traffic can be bursty thus not all can be send within Tc so you never reach CIR.

Niko

[Ahmed Erfan Mehdi]

Hi mya friend,

thanks , how can i tune the bc value

Regards,

Ahmed Erfan

[Joseph W. Doherty]

Disclaimer

The   Author of this posting offers the information contained within this   posting without consideration and with the reader's understanding that   there's no implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not   be construed as rendering professional advice of any kind. Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In   no event shall Author be liable for any damages whatsoever (including,   without limitation, damages for loss of use, data or profit) arising  out  of the use or inability to use the posting's information even if  Author  has been advised of the possibility of such damage.

Posting

Ahmed Erfan Mehdi wrote:
Hi mya friend,
thanks , how can i tune the bc value
Regards,
Ahmed Erfan

Do you mean how you configure on what it should be configured to?

If the former, you just manually configure the BC with the police statement.

If the latter, that's rather complex.  It's can be similar to tuning interface buffers.  For your purposes, just try increasing, incrementally, until your users get the performance they expect.

[Ahmed Erfan Mehdi]

Hi My friend,

Thanks for your reply.

Right now i have set policy limit to 4400 Mbps and he is geting it right.

I want it to be 4354 Mbps, so how can i configure bc manually, how can i calculate the right value to fit the require band.

Regards,

Ahmed Erfan

[Ahmed Erfan Mehdi]

Hi my friend,

we can calculate it as below:

Bc (normal burst) = CIR / 8 * 1.5 seconds

4354000000/8  * 1.5 = 816375000

What do you think ?

[Joseph W. Doherty]

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

Right now i have set policy limit to 4400 Mbps and he is geting it right.
I want it to be 4354 Mbps, so how can i configure bc manually, how can i calculate the right value to fit the require band.

Policing may not be sufficiently precise to distinguish that fine a bandwidth difference, especially over a short time interval.

Remember, unlike an interface that is actually transmitting bits at a physical rate, policers are averaging bits transmitted per packets and they pass or drop packets.