[e2e] Explicit Transport Error Notification

James Sterbenz jpgs at bbn.com
Tue Apr 2 15:03:36 PST 2002

At 02:12 PM 4/2/2002 -0800, Christian Huitema wrote:
 >> Will Ivancic wrote:
> > This work represents a very good start to investigations into ETEN.  I
> > would appreciate any feedback related to the work.  In particular,
> > thoughts on whether or not the potential performance improvements would
> > justify deployment.  If deployment is justified, which areas of research
> > may be best to address?
>Explicit error notification is just one way to distinguish between losses 
>due to transmission errors and losses due to congestion. An alternative 
>way is to use explicit congestion notification, and assume that packet 
>losses are due to other factors -- e.g., only shrink the window on ECN, 
>and expend it on the ACK. There are obvious deployment issues, but these 
>could be solved if NASA is operating in any kind of controlled set-up. In 
>any case, the ECN only option could be simulated in NS...

This is discussed in the report, but it is not quite so simple.  That is, a 
given packet can
cause congestion, and then also suffer a channel error.  So it is not true 
that you can
directly compute corruption from ECN or congestion from ETEN in the case of 
lossy congested


James P.G. Sterbenz                                      jpgs at bbn.com
Senior Network Scientist                                 jpgs at acm.org
Research Group Manager                                +1 617 873 5063
Internetwork Research, BBN Technologies

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