Re: Why was hop by hop flow control eventually abandonded?

agree.
switch is hard to support compliacted states and logics, due to the
performance requirement and the hardware limitation.
however, it would be a worthy idea in SDN, where more flexibility can
be provided by the stateful controller.

On 7/16/13, Noel Chiappa <[email protected]> wrote:
>     > From: Detlef Bosau <[email protected]>
>
>     > the decision to abandon hop by hop flow control
>     > ...
>     > Does anyone happen to know, whether this was decision for a concrete
>     > reason and the rational behind it? Or did this "simply happen"?
>
> Probably the internet-history list is a better place to ask this?
>
> I don't know for sure, but having arrived on the scene shortly thereafter,
> and knowing intimately what packet switches were like then, my _guess_
> is that it had to do with state.
>
> It seems to me that to be able to do hop-by-hop flow control, you have to
> have some state in the switches, yes? (I can't see a way to do it without.)
>
> And in a 'smallish' network, like the ARPANET, it's reasonable to have that
> state. But when you're talking about (potentially) a much bigger network,
> as
> the Internet even then was planned to be, the amount of state potentially
> needed would quite likely have been too much for the switches of the day.
>
> 	Noel
>

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Baohua