From: Thor Kopp (thorkopp@googlemail.com)
Date: Mon Jun 30 2008 - 07:00:46 ART
Just to clarify for my own understanding is the difference between the below
that a) shape average would allow you to burst up to a maximum of 512k if
you have accumulate credit but the normal transmission rate would be
128k based on byte limit is 8000bytes => 8000*8bits*(1/.125) = 512k.
The shape peak config allows you to have a sustained transmission rate of
512k?
Rack9R6(config)#
policy-map SHAPE
class class-default
shape average 128000 16000 48000
Rack9R6(config)#do show policy-map inter
FastEthernet0/0
Service-policy output: SHAPE
Class-map: class-default (match-any)
1 packets, 60 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: any
Traffic Shaping
Target/Average Byte Sustain Excess Interval Increment
Rate Limit bits/int bits/int (ms) (bytes)
128000/128000 8000 16000 48000 125 2000
Adapt Queue Packets Bytes Packets Bytes Shaping
Active Depth Delayed Delayed Active
- 0 1 60 0 0 no
***
Rack9R6(config)#
policy-map SHAPE
class class-default
shape peak 128000 16000 48000
where rate = 128 x (1 + (48000/16000)
Rack9R6(config-pmap-c)#do show policy-map inter
FastEthernet0/0
Service-policy output: SHAPE
Class-map: class-default (match-any)
28 packets, 2962 bytes
5 minute offered rate 0 bps, drop rate 0 bps
Match: any
Traffic Shaping
Target/Average Byte Sustain Excess Interval Increment
Rate Limit bits/int bits/int (ms) (bytes)
512000/128000 8000 16000 48000 125 8000
Adapt Queue Packets Bytes Packets Bytes Shaping
Active Depth Delayed Delayed Active
- 0 28 2962 0 0 no
- Thor
On Mon, Jun 30, 2008 at 7:53 AM, Narbik Kocharians <narbikk@gmail.com>
wrote:
yes based on what i am understanding.
On Sun, Jun 29, 2008 at 11:48 PM, Huan Pham <Huan.Pham@peopletelecom.com.au>
> wrote:
>
> > Hi Narbik,
> >
> > Thanks for your explaination. May I know what would be the best answer to
> > this question. Obviously, the first part of it will be answered by
> bandwidth
> > 128 command. I am more intrested in how you work out the parameter for
> the
> > second part. I mean, should we leave Be, Bc default, and just configure
> > shape peak with CIR = 256. Many thanks.
> >
> >
> > "Assign WEB traffic the minimum of 128K, and allow it to peak at 512K"
> >
> >
> > ------------------------------
> > *From:* Narbik Kocharians [mailto:narbikk@gmail.com]
> > *Sent:* Monday, 30 June 2008 3:40 PM
> > *To:* Huan Pham
> > *Cc:* ccielab@groupstudy.com
> > *Subject:* Re: shape peak and shape average confusion
> >
> > When you need to shape the traffic, there are two types of shaping
> > available to you:
> >
> > *Average rate shaping:* Average rate shaping limits the transmission rate
> > to the CIR. Using the CIR ensures that the average amount of traffic
> being
> > sent conforms to the rate expected by the network.
> >
> > *Peak rate shaping:* Peak rate shaping configures the router to send more
> > traffic than the CIR. To determine the peak rate, the router uses the
> > following formula:
> >
> > *Peak rate = CIR(1+Be/Bc)*
> >
> > Remember that with Shape Peak, shaping allows the router to burst higher
> > than average rate shaping. However, the traffic sent above the CIR
> *CAN*be dropped if the network becomes congested.
> >
> >
> > On Sun, Jun 29, 2008 at 8:31 PM, Huan Pham <
> Huan.Pham@peopletelecom.com.au>
> > wrote:
> >
> >> I am not sure about using shape peak command. Appreciate if someone can
> >> share some clarification.
> >>
> >> The most confusing fact is that if you configure "shape peak 512000",
> >> without optional Bc and Be parrameters (i.e. using default), you are
> >> actually allow traffic to burst to 1024K (double the configured rate).
> >>
> >>
> >> R5#
> >> !
> >> policy-map SHAPE
> >> class WEB
> >> shape peak 512000
> >>
> >> int s0/0
> >> service-policy output SHAPE
> >>
> >> R5# sh policy-map int s0/0
> >>
> >> Serial0/0
> >>
> >> Service-policy output: SHAPE
> >>
> >> Class-map: WEB (match-all)
> >> 0 packets, 0 bytes
> >> 5 minute offered rate 0 bps, drop rate 0 bps
> >> Match: protocol http
> >> Traffic Shaping
> >> Target/Average Byte Sustain Excess Interval
> >> Increment
> >> Rate Limit bits/int bits/int (ms) (bytes)
> >>
> >> 1024000/512000 3200 12800 12800 25 3200
> >>
> >>
> >> Adapt Queue Packets Bytes Packets Bytes Shaping
> >> Active Depth Delayed Delayed Active
> >> - 0 0 0 0 0 no
> >>
> >> Class-map: class-default (match-any)
> >> 223 packets, 2899 bytes
> >> 5 minute offered rate 0 bps, drop rate 0 bps
> >> Match: any
> >>
> >>
> >>
> >> So how will you best answer this question?
> >>
> >> Assign WEB traffic the minimum of 128K, and allow it to peak at 512K.
> >>
> >>
> >> _______________________________________________________________________
> >> Subscription information may be found at:
> >> http://www.groupstudy.com/list/CCIELab.html
> >>
> >>
> >>
> >>
> >>
> >
> >
> > --
> > Narbik Kocharians
> > CCSI#30832, CCIE# 12410 (R&S, SP, Security)
> > www.Net-Workbooks.com <http://www.net-workbooks.com/> <
> http://www.net-workbooks.com/>
> > Sr. Technical Instructor
> >
>
>
>
> --
> Narbik Kocharians
> CCSI#30832, CCIE# 12410 (R&S, SP, Security)
> www.Net-Workbooks.com <http://www.net-workbooks.com/>
> Sr. Technical Instructor
>
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
>
>
>
-- Thanks, Thor
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