Re: Policing and dropping packets

The question is way confusing, because it says "burst RATE exceeds xxx
bits", and that is formally wrong because bits is not a rate unit.

-Carlos

Joe Astorino @ 20/07/2011 19:31 -0300 dixit:
> I believe B is correct. The burst parameters are in terms of bytes, not
> bits. 8000 bytes = 64,000 bits. Also, the burst is not a rate in terms of
> something like bits or bytes per second. The burst values are NOT rates.
> They are literally the size of the token bucket. So, if you configure a BE
> here of 8000 bytes you are not saying the burst is 8000 bytes or 64,000 bits
> PER SECOND, you are just saying the size of the BE token bucket that is used
> to sustain bursts is 8000 bytes. The size of that token bucket mixed with
> time and the policed rate determine how much burst you can actually sustain
>
> HTH man
>
> On Wed, Jul 20, 2011 at 5:59 PM, Tom Kacprzynski <tom.kac_at_gmail.com> wrote:
>
>> Hello,
>> I am reviewing few QoS questions I got to study. The question is:
>>
>> "Using CBWFQ Policing with command:
>> police 100000 5000 8000 conform-action transmit exceed-action
>> set-qos-transmit 4 violate-action drop.
>> When will the router begin to drop packets?"
>>
>> a. when burst rate exceeds 100000 bits
>> b. when burst rate exceeds 64000 bits
>> "
>>
>> I thought A, but the answer sheet says B. So my questions which is right?
>> Why would you set something to police at 100 kbps when you'll start getting
>> packets dropped at 64 Kbps...doesn't make sense.
>>
>> Can someone else please verify and explain?
>>
>> Thank you,
>>
>> Tom
>>
>>
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-- 
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
Blogs and organic groups at http://www.ccie.net