From: Scott Morris (smorris@internetworkexpert.com)
Date: Sat Sep 13 2008 - 00:44:02 ART
No, the example is not incorrect... it's just more detailed a question than
the original one was! :)
If you have multiple PVCs on a single physical interface, and you are trying
to find ways to balance against them, it's possible that any ONE PVC may
cause local congestion.
If you want to find ways to throttle back some pvc's, while others enjoy
unhindered access then this gives you a way of doing it.
MQC on your physical link can give you the ability to do this as well! :)
So the example on the docs is correct, but if you had only one pvc, it would
be silly (IMHO) to deploy something like that. Less throughput, same input
rate = more congestion than before!
Perspective...
Scott
_____
From: Huan Pham [mailto:pnhuan@yahoo.com]
Sent: Friday, September 12, 2008 10:35 PM
To: 'Ali Mousawi'; 'Julian Pentermann'; Scott Morris
Cc: 'Cisco certification'
Subject: RE: Shaping
Hi Scott,
What you said does make sense.
However, if there're more than one PVCs, then in case of interface
congestion (introduced by traffic going to one particular PVC), we may want
to protect traffic going to other PVCs and by limiting less important
traffic going to one particular PVC. Does this make sense as well?
Can you please comment on the below example from the Command Reference which
is directly relevant to the question being asked. Did you mean that the
below information is wrong?
http://cisco.com/en/US/docs/ios/wan/configuration/guide/wan_afrt_shp_ic_ps63
50_TSD_Products_Configuration_Guide_Chapter.html
Frame Relay Adaptive Traffic Shaping for Interface Congestion Example
In the following example, the rate of traffic destined for PVC 200 will be
reduced to the minCIR if the number of packets in the interface queue
exceeds 10. When the number of packets in the interface queue drops below
10, then the traffic rate will immediately return to the CIR.
interface serial0
encapsulation frame-relay
frame-relay traffic-shaping
frame-relay interface-dlci 200
class adjust_vc_class_rate
!
map-class frame-relay adjust_vc_class_rate
frame-relay cir 64000
frame-relay mincir 32000
frame-relay adaptive-shaping interface-congestion 10
--- On Sat, 9/13/08, Scott Morris <smorris@internetworkexpert.com> wrote:
From: Scott Morris <smorris@internetworkexpert.com>
Subject: RE: Shaping
To: "'Ali Mousawi'" <mousawi.ali@gmail.com>, "'Julian Pentermann'"
<jpentermann@gmail.com>
Cc: "'Cisco certification'" <ccielab@groupstudy.com>
Date: Saturday, September 13, 2008, 7:03 AM
"congestion" is a multi-faceted idea.
Congestion in an outbound direction (e.g. your side) will not lead to
mincir. That would be silly. If you are having congestion, what would you
expect if you further reduced your transmission capabilities! :)
Congestion from the frame cloud though is different. A FECN/BECN can signal
there is congestion occurring, in which case it would make perfect sense to
limit the outbound transmssion rate.
HTH,
Scott Morris, CCIE4 #4713, JNCIE-M #153, JNCIS-ER, CISSP, et al.
CCSI/JNCI-M/JNCI-ER
Senior CCIE Instructor
smorris@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
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-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Ali
Mousawi
Sent: Friday, September 12, 2008 4:55 PM
To: Julian Pentermann
Cc: Cisco certification
Subject: Re: Shaping
Thanks for the reply.
I have read some where that adaptive-shaping is used in conjuction with
mincir. Up to my understanding if there is congestion shaping will drop to
mincir .. is that right? but the interface-congestion is new to me can u
please elaborate a bit on that.
Thanks
On Fri, Sep 12, 2008 at 1:45 PM, Julian Pentermann
<jpentermann@gmail.com>wrote:
> Configure adaptive shaping under your map-class as follows
> frame-relay adaptive-shaping interface-congestion 11
>
> im assuming you know the basic FRTS config.
>
> Cheers,
> Julian
>
>
> On Fri, Sep 12, 2008 at 10:38 PM, Ali Mousawi
<mousawi.ali@gmail.com>wrote:
>
>> Hello,
>>
>> Task: Limit HTTP traffic to 256kbps on the fram-relay link.Traffic
>> should drop to min CIR when the queue contains more than 10 packets
>> (Do not use
>> MQC)
>>
>> I am stuck.. any clues??
>>
>> Regards
>> Ali
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
>> _____________________________________________________________________
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