[nsp] Fwd: IP QoS with FR/ATM?

Kent Yu kyu@opnet.com
Thu, 10 Oct 2002 12:58:55 -0400


http://www.cisco.com/warp/public/788/voice-qos/voip-ov-fr-qos.html

Based on this paper, there are actually two subsystems, layer 3 and layer 2.

I tried some configs, seems to me that you could do queuing at both levels
at the same time, but it does not allow you to have scheduling at both
levels i.e. if you have multiple queues for one pvc at layer 3, that pvc can
only have one shaping queue at layer 2.

Router(config-map-class)#frame-relay fair-queue
Must remove frame-relay vc service policy

--kent
----- Original Message -----
From: "JJ" <yulingna@yahoo.com>
To: "Tom Scott" <telecomtom@vedatel.com>; <cisco-nsp@puck.nether.net>
Sent: Wednesday, October 09, 2002 10:44 AM
Subject: Re: [nsp] Fwd: IP QoS with FR/ATM?


> Tom,
>
> That was not what I was asking for.
>
> I am trying to figure out if I have IP QoS and ATM/FR
> traffic shaping, does IOS first put the packets into
> ip queues and then move them into ATM/FR queues?
>
> If this is true then there must be two sets of
> buffers/buckets, but I never seen a diagram like this
> from any cisco docs. In the book IP QoS from cisco
> press, the author does not describes this in detail,
> just mentions something like pvc queueing and you can
> user different shemes like cbwfq or priority queueing,
> but never says if there are two level of queues or
> just one?
>
> thanks
>
> jj
>
> --- Tom Scott <telecomtom@vedatel.com> wrote:
> > J,
> >
> > You could be asking about the mechanics of how the
> > cells, frames and packets
> > get "marked". I don't know if Cisco has shared that
> > with us (customers). But
> > I remember finding something about L3-to-L2 QoS
> > mappings in one of the many
> > CCO docs I've browsed, and I even put the chart on a
> > wall, something like
> > this:
> >              L2     L3 IP         L3
> >              CoS    Precedence    DSCP
> > voice RTP    5      5             EF
> > voice RTCP   3      3             AF31
> > video        4      4             AF41
> > data         0-2    0-2           0-AF23
> >
> > Beware of typos.
> >
> > -- TT
> >
> >
> > JJ wrote:
> > >
> > > Trying to emphasis my confusion:
> > > since the atm/fr vcs have cbr, vbr or cir, so they
> > > must have queues per pvc for cells or frames, ip
> > qos
> > > such as CBWFQ has queues for different classes of
> > ip
> > > packets, how do they work together?
> > >
> > > Thanks
> > >
> > > --- JJ <yulingna@yahoo.com> wrote:
> > > > Date: Tue, 8 Oct 2002 20:17:26 -0700 (PDT)
> > > > From: JJ <yulingna@yahoo.com>
> > > > Subject: IP QoS with FR/ATM?
> > > > To: cisco-nsp@puck.nether.net
> > > >
> > > > I am trying to understand how ip qos works with
> > FR
> > > > and
> > > > ATM.
> > > >
> > > > I read that both FR and ATM do per vc queueing,
> > is
> > > > this true?
> > > >
> > > > If I configure CBWFQ udner one fr or atm pvc,
> > does
> > > > the
> > > > router have two sets of queues? one set for
> > > > different
> > > > classes of ip packets, after the ip packet got
> > > > dequeued from the ip layer, they will be queued
> > > > again
> > > > under that pvc? is it same for fr and atm?
> > > >
> > > > I can not find anything from cco, all of the qos
> > > > docs
> > > > either explain ip qos or atm/fr qos.
> > > >
> > > > thanks for any help.
> > > >
> > > > JJ
> > _______________________________________________
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