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Re: Bandwidth sharing on links from two different LSPs.

  • From: "Ta,Phong G." <pta@mitre.org>
  • Date: Wed, 15 Aug 2001 22:07:07 -0400
  • CC: Sivaramakrishna Iyer Krishnan <krishnan@research.bell-labs.com>, MPLS Operations <mpls-ops@mplsrc.com>
  • Organization: The MITRE Corporation
  • Resent-Date: Wed, 15 Aug 2001 23:44:34 -0400
  • To: raszuk@cisco.com

Robert and Siva,

> It only makes sens if you are doing 100% of traffic engineering in your IP core and limited multicast.

But if one of your LSPs is down, some traffic will take the shortest
path.  Hence it is not 100% of TE anymore.  So even if you are reserving
bandwith, you cannot guarantee that bandwith will be available all time.

Phong

Robert Raszuk wrote:
> 
> Siva,
> 
> > What is the use of reserving bandwidth in control plane if does not get reflected in
> > data plane ?.
> 
> It only makes sens if you are doing 100% of traffic engineering in your
> IP core and limited multicast. If you are not specifing bw=0 while
> building your TE-LSPs will be as good as any other bw from the data
> plane point of view.
> 
> R.
> 
> > Sivaramakrishna Iyer Krishnan wrote:
> >
> > >
> >
> > Hi Robert,
> >
> > > [Assuming we are switching back to the TE-LSPs]
> > >
> > > One more time :).. Control plane wise yes you have two tunnels and both
> > > have some control plane reservations. In the data plane this is not
> > > reflected.
> >
> > What is the use of reserving bandwidth in control plane if does not get reflected in
> > data plane ?.
> >
> > Is this just to reserve the bandwidth so that you know that QoS can be met and then
> > do CAR or queuing on the router so that we see it applied on the data too.
> >
> > > Packets comming into R3 will exit to R4 via the same
> > > interface and it is up to the QoS scheduler on this interface and EXP
> > > field carried in the packets to correctly forward them out.
> >
> > So, in my case where I wanted only 10 Mbps of traffic to be flowing through R3 for
> > traffic emanating from H1 and H2, I need to do QoS at R3. Is it only QoS ?. Do I
> > need to do CAR also for limiting rate or is there some other way to do it ?.
> >
> > Sorry for a lot of questions and thanks for all your answers.
> >
> > Thanks,
> > Krishnan.
> 
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Phong Ta 

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