Subject: Re: [PCN] Corridor discussion about draft-satoh

From: SATOH Daisuke <[email-masked]>
Date: Fri, 27 Mar 2009 11:24:23 +0900

Hi Phil and All,

>
> These are my understanding. I have not confirmed it by simulation yet.
>
> >
> > These are my understanding. I have not confirmed it by simulation yet.
> >
> > [phil] i dont agree with your analysis. after termination from 2* overload to 1.25* overload, why is the traffic any more bursty than if you started with 1.25* overload?????
> >
> 
> We compare original 1.25*supportable rate (SR) with 1.25 SR after
> termination.
> 
> The traffic after termination has very bursty traffic in a short
> period because traffic before termination stays in a short period even
> after termination. This high rate state does not exist in the original
> 1.25 SR traffic. But both rate is the same. Thus the traffic after
> termination has traffic with lower rate than the original 1.25*SR in a
> short period. Therefore traffic after termination includes both higher
> and lower rate than the original 1.25*SR. Traffic after termination is
> more bursty than the original 1.25*SR traffic.
> 
> [phil] dont follow. let me try to re-phrase, is the problem this:-
> you have VBR traffic with on & off periods. in your first round of termination you terminate flows that all tend to be ON at the same time. therefore after termination the other flows also tend to be On at the same time, so you still see that the link is overloaded. 
> if this is the problem, this problem has nothing to do with the marking algorithm. it's either a problem with the edge behaviour or (more likely) it's a problem of syncronisation in your simulation. 
> 
> 

Please see all the termination results of CBR in my simulation. The same
phenomenon can be seen. There is no relation to VBR. This problem is
caused by SAR. SAR is strongly connected excess traffic marking that
marking behaviour draft defines. 

Best regards,
Daisuke