[109175] in North American Network Operators' Group
Re: ECN
daemon@ATHENA.MIT.EDU (Hank Nussbacher)
Sat Nov 8 11:31:58 2008
Date: Sat, 8 Nov 2008 18:31:43 +0200 (IST)
From: Hank Nussbacher <hank@efes.iucc.ac.il>
To: Valdis.Kletnieks@vt.edu
In-Reply-To: <27621.1226079082@turing-police.cc.vt.edu>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
On Fri, 7 Nov 2008, Valdis.Kletnieks@vt.edu wrote:
> On Fri, 07 Nov 2008 08:27:58 +0100, Mikael Abrahamsson said:
>> for ECN to actually be useful, we (the ISPs) have to turn this option on
>> in the routers as well. Is anyone doing this today? What vendors support
>> it?
>
> The only thing that's *required* for it to help is that the routers and
> firewalls not actually *molest* the bits in the TCP SYN packet. If you pass
> them and *do nothing else*, it at least has the potential of being useful at
> some other router along the path. And let's face it - if *your* router is
> congested enough for ECN to matter, there's a fairly good chance that the
> router one hop up/downstream is *also* seeing some effects. Even if *you* don't
> do anything else, your neighbor might - helping you out in the bargain.
See:
http://www.icir.org/floyd/ecn.html
http://www.cisco.com/en/US/docs/ios/12_2t/12_2t8/feature/guide/ftwrdecn.html
-Hank
