An "Internet variable speed limit" is a nice idea, but there are some serious trust issues; applications have to trust the network implicitly not to issue gratuitous slow down messages, and certainly not to use them for evil purposes (not that I want to start a network neutrality flamewar...but what with the AT&T/Pearl Jam row, it's not hard to see rightsholders/telcos/government/alien space bats leaning on your upstream to spoil your access to content X).
<br><br>Further, you&#39;re going to need *very good* filtration; necessary to verify the source of any such packets closely due to the major DOS potential. Scenario: Bad Guy controls some hacked machines on AS666 DubiousNet, who peer at AMS-IX. Bad Guy has his bots inject a mass of &quot;slow down!&quot; packets with a faked source address taken from the IX&#39;s netblock...and everything starts moving Very Slowly. Especially if the suggestion upthread that the slowdown ought to be implemented 1-2 AS away from the problem is implemented, which would require forwarding the slowdowns between networks.
<br><br>It has some similarities with the Chinese firewall&#39;s use of quick TCP RSTs to keep users from seeing Bad Things; in that you could tell your machine to ignore&#39;em. There&#39;s a sort of tragedy of the commons problem - if everyone agrees to listen to the slowdown requests, it will work, but all you need is a significant minority of the irresponsible, and there&#39;ll be no gain in listening to them.
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