[e2e] TCP behaviour in the presence of reverse traffic (Vegas, New Reno, Westwood+, Fast?)

[Saverio Mascolo]

i think so
saverio
----- Original Message -----
From: "Jing Shen" <jshen_cad at yahoo.com.cn>
To: <lz6 at njit.edu>; "Saverio Mascolo" <mascolo at poliba.it>
Cc: <end2end-interest at postel.org>
Sent: Friday, November 14, 2003 12:31 PM
Subject: Re: [e2e] TCP behaviour in the presence of reverse traffic (Vegas,
New Reno, Westwood+, Fast?)


> Does that means the two ends need to sync. time or the
> like?
>
>
>
> jing shen
>
>
>  --- lz6 at njit.edu |¨¬??y???¨ºo> Hi, Saverio,
> >
> > The paper "An Enhanced Congestion Avoidance
> > Mechanism for TCP Vegas"(IEEE
> > COMMUNICATIONS LETTERS, VOL. 7, NO. 7, JULY 2003)
> > provided a fix to the problem
> > mentioned in your post. The basic idea of that paper
> > is to use forward path
> > delay to calculate queueing delay instead of using
> > rtt to do so. But this
> > requires TCP receiver to add "extra" timestamp in
> > the ACK packet, which
> > is "legal" as I remember.
> >
> > Li
> >
> >
> > Quoting Saverio Mascolo <mascolo at poliba.it>:
> >
> > > The link below shows some results we have obtained
> > by simulating (in
> > > ns-2)
> > > one TCP connection in the forward direction and
> > one ON-OFF New Reno
> > > TCP
> > > connection going in the backward direction. The
> > backward connection
> > > excites
> > > congestion along the ACK path of the forward
> > connection.
> > >
> > > This scenario clearly shows that an rtt-based
> > congestion detection
> > > mechanism, such as the one of Vegas,  detects
> > false congestion because
> > > of
> > > queuing in the  reverse path. This could be a
> > problem also for Fast
> > > TCP,
> > > which employs rtt-based congestion detection too.
> > >
> > >
> > >
> >
> http://www-ictserv.poliba.it/mascolo/TCP%20Westwood/Reverse/reverse.htm
> > > -----------
> > > Saverio Mascolo
> > >
> > >
> >
>
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