From: ccie2be (ccie2be@nyc.rr.com)
Date: Mon Nov 22 2004 - 10:39:10 GMT-3
Hey Sally,
A couple points.
If only the cir value is set, the bc and be values are set automatically to
default values. To see those default values, do a show policy-map int X.
I also think there's great potential for confusion because if you set the
be value manually, you're not really setting the be value directly. (I
know, it's crazy, but it's not my fault. I didn't write the IOS code.)
When you set the be value, what you're really doing is setting the bc + be
value. So, if you want the be value to be 0, you set the be value to the
same value as the bc value. Why they did that, I have no idea. But, in any
case, here's an example using a single rate and a single bucket:
police at 64k with bc = 8k and be = 0
policy-map POLICE
class TRAFFIC
police 64000 8000 8000 conform-action transmit exceed-action set
fr-de
Notice a couple of things in the above command.
1) cir is in bits, bc and be are in bytes
2) The 2nd 8000 equals bc + be, therefore, if bc = 8000, be = 0.
3) If be = 0, I think all traffic over bc is dropped by default.
I believe, but I'm not 100% sure about this, be must > 0 for the set fe-de
action to take effect. Hopefully, someone will verify this. So, to answer
your question directly, only traffic over 64k bps ( equivalent to 8000 Bps)
will have the fr-de bit set adn then only if excess-burst is non-zero.
To add additional confusion, there are lots of versions of the police
command.
1) single rate, single bucket as shown above
2) single rate, dual bucket - this requires that the violate-action is
specified in the above command
3) 2 rate, dual bucket. Here's an example:
police cir 500000 bc 10000 pir 1000000 be 10000 conform-action transmit
exceed-action set-prec-transmit 2 violate-action drop
4) police based on percentage of bandwidth. For example,
police cir percent 30
These commands are documented in the QoS section of IOS 12.3.
And, as if this wasn't sufficiently confusing, in the DQoS book, the
examples shown seem to use still another varition of the police command.
So, hopefully, I helped clear up a little confusion instead of adding to the
confusion.
Tim
----- Original Message -----
From: "Sally Crawford" <crawford0982003@yahoo.com>
To: "ccie2be" <ccie2be@nyc.rr.com>; <ccielab@groupstudy.com>
Sent: Sunday, November 21, 2004 11:51 PM
Subject: Re: setting the FR-de bit on exceeding bandwidth
> Hello
>
> Thanks for the reply
>
> I have done a few tests, and i could only get the
> DE-bit to be marked when i set the Be value. I belive
> since be=0 by default , then the trafic will never go
> above the desired traffic-shaped rate, unless an
> excess burst is specified
>
> Im still confused though. If the CIR is 64kbps and the
> bc = 8k, and i set the be to something greater than 0,
> does that mean that anything over 72kbps in a single
> burst is marked with a de-bit ( since 64+8= 72) ? or
> is anything over the CIR ( 64k ) set with the de-bit.
>
> Furthermore, if i set the be , to lets say 1k, does
> that mean that anything over 73k is dropped since
> nothing can placed in the token bucket for FRTS
>
> As you can see, im very confused.
>
> Brians, Scott , any thoughts on this
>
> Thanks
> S
>
>
> --- ccie2be <ccie2be@nyc.rr.com> wrote:
>
> > Hi Sally,
> >
> > It looks like it should work but you can test it if
> > you're able to generate
> > more than 64k worth of traffic.
> >
> > I did something similar recently.
> >
> > First, you should know that if you do a show
> > frame-relay pvc, in the output
> > there are a of couple of DE specific fields - 1 for
> > bytes and 1 for packets.
> >
> > So, let's say you have 2 routers rtr-A and rtr-B and
> > you configure rtr-A as
> > below.
> >
> > Before generating traffic, go to rtr-B and do a show
> > fram pvc # and make
> > sure the DE fields are 0. If not, clear the
> > counters. Then, on rtr-A start
> > generating enough traffic so that it exceeds the
> > rate set with your police
> > command. (I'm not sure how do this. Using ping
> > with a high repeat count
> > doesn't seem to generate a very high rate of
> > traffic, so you might need some
> > sort of traffic generator tool.)
> >
> > Then go to rtr-B and check if any packets were
> > received with the DE bit set.
> >
> > HTH, Tim
> >
> >
> > ----- Original Message -----
> > From: "Sally Crawford" <crawford0982003@yahoo.com>
> > To: <ccielab@groupstudy.com>
> > Sent: Sunday, November 21, 2004 6:43 PM
> > Subject: setting the FR-de bit on exceeding
> > bandwidth
> >
> >
> > > Hello ,
> > >
> > > I am trying to set the de-bit for anything over
> > > 64kbps.
> > >
> > > I am using FRTS on the interface .
> > >
> > > policy-map test
> > > class class-default
> > > police cir 64000
> > > conform-action transmit
> > > exceed-action set-frde-transmit
> > >
> > >
> > > map-class frame-relay test1
> > > frame-relay cir 64000
> > > frame-relay bc 8000
> > > service-policy output test
> > >
> > > int s0/0
> > > frame-relay traffice-shaping
> > > frame-relay class test1
> > >
> > > Will this work, considering that TS will shape the
> > > output to 64kbps ?
> > >
> > > thanks
> > > sally
> > >
> > >
> > >
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>
>
>
>
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