From: raul raul (juvenn@hotmail.com)
Date: Fri May 30 2008 - 21:54:01 ART
Ok ; let me go through QOS from IEWB COD / Sadiq help and see what i can find and understand from there
Thanks alot to share with us on narbik lecturer
> From: DAthaide@epco.com> To: juvenn@hotmail.com; ccielab@groupstudy.com> Date: Fri, 30 May 2008 18:21:43 -0500> Subject: RE: shape peak> > I attended Narbik's bootcamp this May and after his excellent lecture on QOS> brought this very example in the DOC CD to his attention. We got the exact> same result as you did and concluded that to get a throughput of 512K> (provided bc=be) we need to set the peak of 256K.> > In any case another student in my class found a better explanation which I> have pasted below. So basically, If I was asked a question like u asked below> which is to set the bandwidth to 300k but if enough bandwidth is available> obtain a throughput upto a peak 512K. I would do the following.> > > Policy qos> Class test> Bandwidth 300> Shape peak 256> > > http://www.ciscopress.com/articles/article.asp?p=352991&seqNum=9> > Chapter 9> > Consider the following CB-Shaping example, where you are shaping one class-map> to average and another class-map to peak:> Router(!
config)#class-map AVERAGECLASS> Router(config-cmap)#match protocol telnet> Router(config-cmap)#exit> Router(config)#class-map PEAKCLASS> Router(config-cmap)#match protocol http> Router(config-cmap)#exit> Router(config)#policy-map AVERAGEPOLICY> Router(config-pmap)#class AVERAGECLASS> Router(config-pmap-c)#shape average 64000> Router(config-pmap-c)#exit> Router(config-pmap)#exit> Router(config)#policy-map PEAKPOLICY> Router(config-pmap)#class PEAKCLASS> Router(config-pmap-c)#shape peak 64000> In this example, the AVERAGEPOLICY policy-map is shaping Telnet traffic to> average, meaning that Telnet traffic is shaped to the CIR of 64 kbps. However,> that is not the case for the PEAKPOLICY policy-map.> The PEAKPOLICY policy-map is shaping traffic to a peak rate of CIR * [1 +> (Be/Bc)]. Because you let the IOS calculate the Bc and Be values, they are> equal, which means that you are shaping to a rate of 64000 * (1 + 1) = 128> kbps.> > > > From: raul raul [mailto:juvenn@hotmail.com!
]> Sent: Friday, May 30, 2008 8:40 AM> To: Athaide, Dwayne; cc!
ielab@gr
oupstudy.com> Subject: RE: shape peak> > > Hi> > are u sure cisco will make mistake in thier doc cd ?> Anybody pls help to clarify and explain> > > > Thanks> > > > ________________________________> > > From: DAthaide@epco.com> > To: juvenn@hotmail.com; ccielab@groupstudy.com> > Date: Fri, 30 May 2008 08:17:25 -0500> > Subject: RE: shape peak> >> > I think the Cisco example you mentioned below is incorrect in the DOC CD.> If> > you want a throughput of 512K then you will need to do a shape peak of 256K> > (if bc=be).> >> >> >> >> >> > The following example uses peak rate shaping to ensure a bandwidth of 300> > kbps> >> > but allow throughput up to 512 kbps if enough bandwidth is available on the> >> > interface:> >> > bandwidth 300> >> >> >> > shape peak 512000> >> >> >> >> >> >> >> > why is shape peak 512000 on cisco article ?> >> > if i shape peak then i will get 1024000; is this correct ? or other way> round> >> > ? pls explain ? Traffic Shaping Target/Average Byte Sustai !
n> >> > Excess> >> > Interval Increment Rate Limit bits/int bits/int> >> > (ms) (bytes) 1024000/512000 3200 12800 12800> >> > 25 3200> >> >> >> > -----Original Message-----> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of> raul> > raul> > Sent: Thursday, May 29, 2008 10:49 PM> > To: ccielab@groupstudy.com> > Subject: shape peak> >> >> >> > Hi ;> >> >> >> > need help> >> >> >> >> >> > Usage Guidelines> >> > Traffic shaping limits the rate of transmission of data. In addition to> using> >> > a specifically configured transmission rate, you can use Generic Traffic> >> > Shaping (GTS) to specify a derived transmission rate based on the level of> >> > congestion.> >> > You can specify two types of traffic shaping; average rate shapi ng and> peak> >> > 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 configures the router to send more traff!
ic than
the CIR.> To> >> > determine the peak rate, the router uses the following formula:> >> > peak rate = CIR(1 + Be / Bc)> >> > where:> >> > Be is the Excess Burst size.> >> > Bc is the Committed Burst size.> >> > Peak rate shaping allows the router to burst higher than average rate> > shaping.> >> > However, using peak rate shaping, the traffic sent above the CIR (the> delta)> >> > could be dropped if the network becomes congested.> >> > If your network has additional bandwidth available (over the provisioned> CIR)> >> > and the applica tion or class can tolerate occasional packet loss, that> extra> >> > bandwidth can be exploited through the use of peak rate shaping. However,> >> > there may be occasional packet drops when network congestion occurs. If the> >> > traffic being sent to the network must strictly conform to the configured> >> > network provisioned CIR, then you should use average traffic shaping.> >> > Examples> >> > The following example sets the uses average r!
ate shaping to ensure a> > bandwidth> >> > of 256 kbps:> >> > shape average 256000> >> >> >> >> >> > The following example uses peak rate shaping to ensure a bandwidth of 300> > kbps> >> > but allow throughput up to 512 kbps if enough bandwidth is available on the> >> > interface:> >> > bandwidth 300> >> >> >> > shape peak 512000> >> >> & gt;> >> >> >> >> > why is shape peak 512000 on cisco article ?> >> > if i shape peak then i will get 1024000; is this correct ? or other way> round> >> > ? pls explain ? Traffic Shaping Target/Average Byte Sustain> >> > Excess> >> > Interval Increment Rate Limit bits/int bits/int> >> > (ms) (bytes) 1024000/512000 3200 12800 12800> >> > 25 3200> >> > _________________________________________________________________> >> > Manage multiple email accounts with Windows Live Mail effortlessly.> >> > http://www.get.live.com/wl/all> >> >> >> >> >> > _______________________________________________________________________> >> > Subscription informati!
on may be found at:> >> > http://www.groupstudy.com/list/CCIEL!
ab.html>
>> >> > _____________________________________________________________ __________> > Subscription information may be found at:> > http://www.groupstudy.com/list/CCIELab.html> >> >> >> >> > ________________________________> Enrich your blog with Windows Live Writer. Windows Live> Writer<http://get.live.com/writer/overview>> > > _______________________________________________________________________> Subscription information may be found at: > http://www.groupstudy.com/list/CCIELab.html> > > >
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