Re: MQC shape vs peak command confusion

You can specify two types of traffic shaping; average rate shaping and peak
rate shaping. Average rate shaping limits the transmission rate to the CIR,

Peak rate shaping configures the router to send more traffic than the CIR,
using this formula

peak rate = CIR(1 + Be / Bc)

this is from the doc cd,

in the lab I think they will tell you what to do,

if they ask to shape the traffic to 256Kbps peak, then safley you can
configure,

shape peak 256000

check out this link

http://www.cisco.com/en/US/docs/ios/qos/command/reference/qos_s1.html#wp1014690

HTH

Salah

On Sat, Apr 4, 2009 at 10:04 PM, naveen M S <navin.ms_at_gmail.com> wrote:

> Thanks everyone. If I want to achieve peak rate of 128kbps, I still have
> many choices.
>
> 1) Keep CIR = 128kbps and Be = 0. This makes PIR = CIR = 128kbps
> 2) Keep CIR = 85kbps and Be = Bc / 2. This makes PIR = 128kbps
> 3) Keep CIR = 64kbps and Be = Bc. This makes PIR = 128kbps .. etc.
>
> In the lab if the task doesn't say anything about Be, should I assume Be =
> 0 or Be = Bc ?
>
> Regards,
> Naveen.
>
>
> On Sat, Apr 4, 2009 at 11:34 AM, Salah ElShekeil <
> salah.elshekeil_at_gmail.com> wrote:
>
>> be aware that the shape peak formula is not the same as the shaping
>> formula
>>
>>
>>
>> shape peak
>>
>>
>>
>> peak rate = CIR(1 + Be / Bc)
>>
>>
>>
>> shape average (CIR) = bc*1000/tc
>>
>>
>>
>> HTH
>>
>>
>>
>> Salah
>>
>>
>>
>> On Sat, Apr 4, 2009 at 4:40 PM, Ruhann <groupstudy_at_ru.co.za> wrote:
>>
>>> Mr Petr wrote a great article about the shape peak command:
>>>
>>>
>>> http://blog.internetworkexpert.com/2008/08/26/understanding-the-shape-peak-command/
>>>
>>> On Sat, Apr 4, 2009 at 6:27 AM, naveen M S <navin.ms_at_gmail.com> wrote:
>>>
>>> > Group,
>>> >
>>> > Here is my task :
>>> >
>>> > 1) Shape HTTP traffic to a peak rate of 128kbps sent out to Vlan 34.
>>> > 2) Use Bc and Be bursts based on 10ms interval.
>>> >
>>> > *My solution was -*
>>> >
>>> > class-map HTTP
>>> > match protocol http
>>> > policy-map SHAPE
>>> > class HTTP
>>> > * shape peak 128000 1280 0*
>>> > interface gig 0/0
>>> > service-policy output SHAPE
>>> >
>>> > Rack1R1(config-pmap-c)#* do sh policy-map int gig0/0*
>>> > Target/Average Byte Sustain Excess Interval
>>> Increment
>>> > Rate Limit bits/int bits/int (ms) (bytes)
>>> > 128000/128000 160 1280 0 10 160
>>> >
>>> > *The workbook solution was -*
>>> >
>>> > class-map HTTP
>>> > match protocol http
>>> > policy-map SHAPE
>>> > class HTTP
>>> > * shape peak 64000 6400 6400*
>>> > interface gig 0/0
>>> > service-policy output SHAPE
>>> >
>>> > Rack1R1(config-pmap-c)# *do sh policy-map int gig0/0*
>>> > Target/Average Byte Sustain Excess Interval
>>> Increment
>>> > Rate Limit bits/int bits/int (ms) (bytes)
>>> > 128000/64000 1600 6400 6400 100 1600
>>> >
>>> > What difference it makes to the peak output rate when either of the 2
>>> > statements are given ?
>>> >
>>> > 1) shape peak 128000 1280
>>> > 2) shape peak 64000 6400 6400
>>> >
>>> > Thanks,
>>> > Naveen.
>>> >
>>> >
>>> > Blogs and organic groups at http://www.ccie.net
>>> >
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>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>>
>>>
>>> --
>>> <ruhann>
>>>
>>>
>>> Blogs and organic groups at http://www.ccie.net
>>>
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Received on Sat Apr 04 2009 - 22:46:46 ART