From: Petr Lapukhov (petrsoft@gmail.com)
Date: Thu Mar 23 2006 - 04:05:08 GMT-3
David,
i have some thoughts on that one:
policy-map xxx
class class-default
shape average percent 60
fair-queue
random-detect
How that works, in my opinion?
1) All traffic is shaped (delayed) to fit into 60% of interface b/w
( we may have shaping queue here served by WFQ)
2) _After_ that, traffic is served by fair-queue with random-detect DROP
strategy.
Now, will it ever work? Since we have traffic already _throttled to 60% of
interface b/w_
- no, probably not. Congestion will not occur, queue will not start to
overflow.
In my opinion:
1) We should use MQC FRTS with nested policy-map for random-detect,
as i wrote before, OR
2) We should use legacy FRTS for shaping + service policy in class-map
for CBWFQ
HTH
Petr
2006/3/22, david robin <robindavi@gmail.com>:
>
> Dear all,
> let me be more specific the question said exactly:
>
> *All of the traffic that forward F/R cloud will use bandwidth 60%of S0/0
> on
> R5 and before Queue overflow occurs, enable random detect.*
>
> that is the question, no more no less. what i got in my mind is that when
> I
> use the bandwidth command the traffic will not th 60 % of the bandwidth,
> and
> I can't limit all the traffic to use 60 % of the interface except by using
> policing or shaping even after thinking i think the bandwidth command will
> not be usefull too, as I know we can't enable policing with random detect,
> am i right about that ?
>
> the only option I had is using shaping as follow:
>
> policy-map xxx
>
> class class-default
>
> shape average percent 60
>
> fair queue
>
> randon detect
>
> **
>
> *so do you have any thing else in mind, I read the emails and I think
> threshold values in random detect will require dscp and precedence plus it
> is very hard to calculate bw utilization from the values of packets in
> queue
> and with mark probaility denominator.*
>
> *best regards and waiting for all your replies
> *
>
>
> On 3/22/06, Eric.Stuhl@ferguson.com <Eric.Stuhl@ferguson.com> wrote:
> >
> > Sorry, I should have been more specific. I meant WRED, configuring for
> > all viable precedence values.
> >
> >
> >
> > (
> >
>
>
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos_
> c/fqcprt3/qcfwred.htm
> > )
> >
> >
> >
> > Do we have the exact wording of the original question? That might clear
> up
> > any inconsistencies.
> >
> >
> >
> > Eric Stuhl
> >
> > CCNP, CCDP, CCSE-NG
> >
> > Ferguson Enterprises
> >
> > eric.stuhl@ferguson.com
> >
> > (757)-969-4146
> > ------------------------------
> >
> > *From:* Schulz, Dave [mailto:DSchulz@dpsciences.com]
> > *Sent:* Wednesday, March 22, 2006 12:22 AM
> > *To:* Eric Stuhl - 0018 HQ; robindavi@gmail.com
> >
> > *Cc:* ccielab@groupstudy.com
> > *Subject:* RE: random detect under a policy-map
> >
> >
> >
> > Is that the case? Does anyone have any supporting documentation? It is
> > my understanding that the RED kicks in to avoid congestion on the link
> > BEFORE it happens. I can't seem to locate any documentation that
> supports
> > this theory.
> >
> >
> >
> > This may be thinking outside the box, but maybe we could do this with
> > policing....transmit up to 60% of the link speed, then....set an exceed
> > action to set-dscp-transmit. Do this on the incoming interface. Then,
> on
> > the outgoing interface...set the random detect to dscp-based. Just a
> > thought.
> >
> >
> > ------------------------------
> >
> > *From:* Eric.Stuhl@ferguson.com [mailto:Eric.Stuhl@ferguson.com]
> > *Sent:* Tue 3/21/2006 10:13 PM
> > *To:* Schulz, Dave; robindavi@gmail.com
> > *Cc:* ccielab@groupstudy.com
> > *Subject:* RE: random detect under a policy-map
> >
> > I would submit that the threshold for RED is exactly what you're looking
> > for here. If you set a threshold at 60%, at that point RED kicks in and
> > begins to drop packets. Before that time, packets flow normally.
> >
> > Eric Stuhl
> > CCNP, CCDP, CCSE-NG
> > Ferguson Enterprises
> > eric.stuhl@ferguson.com
> > (757)-969-4146
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com<nobody@groupstudy.com>]
> > On Behalf Of
> > Schulz, Dave
> > Sent: Tuesday, March 21, 2006 7:04 PM
> > To: robindavi@gmail.com
> > Cc: ccielab@groupstudy.com
> > Subject: Re: random detect under a policy-map
> >
> > Hmmm, I am not sure if you can control "when" RED is in effect. Other
> > than based on dscp or precedence. Maybe someone else has some ideas on
> > this one.
> >
> > Dave Schulz
> > *** Sent from my Blackberry ***
> >
> > -----Original Message-----
> > From: david robin <robindavi@gmail.com>
> > To: Schulz, Dave <DSchulz@dpsciences.com>
> > CC: Cisco certification <ccielab@groupstudy.com>
> > Sent: Tue Mar 21 18:16:35 2006
> > Subject: Re: random detect under a policy-map
> >
> > yep,
> > thats what i want , if traffic exceed 60 % enable random detect on the
> > interface
> >
> >
> > On 3/21/06, Schulz, Dave <DSchulz@dpsciences.com> wrote:
> >
> > That is an interesting lab question....it appears the first
> > scenario
> > would provide a minimum of 60 percent of the link for all
> > traffic and
> > also do random detect on the same traffic, since they are both
> > part of
> > the same class. The second one is similar, but shaping to 60%
> > and also
> > doing random detect on that traffic. However, the way I read
> > your
> > question is...to only do random detect when the threshold of 60%
> > is
> > exceeded. Is this what you are looking to do?
> >
> >
> > Dave Schulz,
> > Email: dschulz@dpsciences.com
> >
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com<nobody@groupstudy.com>]
> > On
> > Behalf Of
> > david robin
> > Sent: Tuesday, March 21, 2006 3:20 PM
> > To: Cisco certification
> > Subject: random detect under a policy-map
> >
> > dear all,
> > I have a question, if said all traffic on an interface will use
> > 60 % and
> > you
> > must enable random detection if traffic pass this limit,
> > I have 2 things in minds but i dont know who will be the correct
> > answer.
> >
> > 1- by using the bandwidth command
> >
> > policy-map xx
> > class all-traffic
> > bandwidth percent 60
> > random detect
> > !
> > where class all-traffic will match all the traffic
> > but as far as I know the bandwidth command will not reserve the
> > 60 %
> > untill
> > there is a congetion on the physical interface itself, and
> > random detect
> > will not work there is a main interface congestion and the
> > traffic will
> > exceed 60 % Am i right about that ????
> >
> >
> > 2- by using the shaping command and i think this will be the
> > right
> > answer:
> >
> > policy-map xx
> > class all-traffic
> > shape average percent 60
> > random detect
> > !
> > I think this will be the solution?
> > any comment or any other solutions about that?
> >
> >
> > _______________________________________________________________________
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