[e2e] Why was hop by hop flow control eventually abandonded?

Detlef Bosau detlef.bosau at web.de
Tue Jul 16 12:35:38 PDT 2013

Am 16.07.2013 19:43, schrieb Ted Faber:
> One of the many interesting ideas in Dina Katabi's XCP work is that she
> distributes the per-flow/per-switch data into the packets of the flow.
> It's not an obvious idea (in my dumb opinion) and reading about XCP with
> that in mind is worthwhile.
> I think at its core congestion control is an end-to-end problem, not so
> much because of state in elements (though that does matter) but
> diversity of elements.  End-to-end congestion control makes TCP over
> avian carriers possible.

Hm. This exhibits an interesting twist of the loss differentiation 
problem ;-)

However, I doubt TCP over Avian Carriers would allow a "coddle" 
implementation which would be acceptable for PETA ;-)
> There are many elements in a network path that can become a flow's
> bottleneck.


> There's no way to guarantee that the thing that's
> bottlenecked is also smart enough (or honest enough) to participate in
> hop-by-hop congestion control.  An end-to-end system can assess the path
> and make decisions without cooperation of internal elements (though an
> end-to-end system can make use of cooperation that it can get).  No
> matter what's slowing your pigeons down, an end-to-end congestion
> control will react to it.  Eventually. :-)

Oh yeah.... Hopefully, no PETA members become aware of this discussion....

Detlef Bosau
Galileistraße 30
70565 Stuttgart                            Tel.:   +49 711 5208031
                                            mobile: +49 172 6819937
                                            skype:     detlef.bosau
                                            ICQ:          566129673
detlef.bosau at web.de                     http://www.detlef-bosau.de

More information about the end2end-interest mailing list