Re: [PCN] Concensus questions from Thursday's PCN meeting

[<[e-mail]>]

Ok - you'd forgotten to remind us of that!
Note that you're making the assumption of SM [for CL (is excess rate
marking just for termination) the requirement is to see one mark.]

> -----Original Message-----
> From: Georgios Karagiannis [mailto:[e-mail]]
> Sent: 19 March 2008 16:10
> To: Eardley,PL,Philip,CXR9 R; [e-mail]
> Cc: [e-mail]
> Subject: RE: [PCN] Concensus questions from Thursday's PCN meeting
> 
> Hi Phil
> 
> But in order to trigger the admission control and flow termination,
> the situation CLE > 1% has to be first triggered.
> 
> Best regards,
> Georgios
> 
> 
> > -----Original Message-----
> > From: [e-mail] [mailto:[e-mail]]
> > Sent: woensdag 19 maart 2008 17:07
> > To: [e-mail]; [e-mail]
> > Cc: [e-mail]
> > Subject: RE: [PCN] Concensus questions from Thursday's PCN meeting
> >
> > Georgios,
> >
> > I notice you refer to CLE below. Note that for termination
> > the relevant parameter is the Sustainable rate, that is the
> > rate of unmarked pkts (or, if SM being used, this rate is
> > multiplied by the domain-wide parameter U).
> >
> > phil
> >
> > > -----Original Message-----
> > > From: [e-mail] [mailto:[e-mail]] On
> > Behalf Of
> > > Georgios Karagiannis
> > > Sent: 19 March 2008 15:49
> > > To: 'Steven Blake'
> > > Cc: [e-mail]
> > > Subject: Re: [PCN] Concensus questions from Thursday's PCN meeting
> > >
> > > Hi Steven
> > >
> > > Okay, I will have to spend some time on this!
> > >
> > > Best regards,
> > > Georgios
> > >
> > >
> > > > -----Original Message-----
> > > > From: Steven Blake [mailto:[e-mail]]
> > > > Sent: woensdag 19 maart 2008 16:43
> > > > To: Georgios Karagiannis
> > > > Cc: [e-mail]
> > > > Subject: RE: [PCN] Concensus questions from Thursday's PCN
meeting
> > > >
> > > > On Wed, 2008-03-19 at 16:24 +0100, Georgios Karagiannis wrote:
> > > >
> > > > > Hi Steven
> > > > >
> > > > > Please see that I have included some information into the
> > > > last bullet:
> > > > >
> > > > > - There is an ingress-egress aggregate whose traffic is
> > > > split across
> > > > > multiple paths via ECMP.
> > > > >  - Traffic is admitted along this split path.
> > > > >  - One (or more) of the paths fails.
> > > > >  - One (or more) of the remaining paths becomes severely
> > > > congested (for
> > > > >    example because there is traffic from other ingress-egress
> > > > > aggregates flowing along that path).
> > > > > - <<Due to the ECMP routing not congested paths will
> > > > forward packets
> > > > > belonging to
> > > > >   the same ingress-egress-aggregate that will be unmarked.>>
> > Marked
> > > > > packets are
> > > > >   preferentially dropped at the severely congested
> > > > >   router(s). As a consequence, not enough marked traffic
arrives
> > at
> > > > > the egress router to drive the CLE for the ingress-egress
> > aggregate
> > > > > above the threshold needed to trigger a response (termination,
> > say).
> > > >
> > > > Ok.  To be specific, the egressrouter  will see some fraction of
> > > > packets from the severely congested router(s), some of
> > which will be
> > > > marked, and will see a larger fraction of un-marked
> > packets from the
> > > > un-pre-congested routers.
> > > >
> > > > So let me now ask you this: given N ECMP paths (after a path
> > > > failure), with one being severely congested and the rest being
> > > > un-pre-congested, and given a CLE threshold CLE_thresh at
> > the egress
> > > > router, can you solve for the minimum PCN_lower_threshold
> > value at
> > > > the severely congested router, where PCN still works (e.g., CLE
> > > > crosses the threshold), for the two cases where (1)
> > marked packets
> > > > are preferentially dropped, and (2) marked packets are
> > dropped with
> > > > equal probability with un-marked packets?
> > > >
> > > >
> > > >
> > > > Regards,
> > > >
> > > > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> > > > Steven Blake                <[e-mail]>
> > > > Ericsson/Redback Networks               [phone]
> > > >
> > >
> > >
> > > _______________________________________________
> > > PCN mailing list
> > > [e-mail]
> > > https://www.ietf.org/mailman/listinfo/pcn
> >
> 

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