Re: [hybi] Last Call: <draft-ietf-hybi-thewebsocketprotocol-10.txt>

Martin Rex <mrex@sap.com> Fri, 29 July 2011 02:38 UTC

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From: Martin Rex <mrex@sap.com>
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To: marka@isc.org (Mark Andrews)
Date: Fri, 29 Jul 2011 04:38:12 +0200 (MEST)
In-Reply-To: <20110728020118.647E1123AED8@drugs.dv.isc.org> from "Mark Andrews" at Jul 28, 11 12:01:18 pm
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Cc: hybi@ietf.org, ietf@ietf.org, mrex@sap.com
Subject: Re: [hybi] Last Call: <draft-ietf-hybi-thewebsocketprotocol-10.txt>
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Mark Andrews wrote:
> 
> Martin Rex writes:
> >
> > Mark Andrews wrote:
> > > 
> > > More correctly it is try the first address and if that doesn't
> > > connect in a short period (150...250ms) start a second connection
> > > to the next address while continuing with the first.  If you have
> > > more that 2 address you do something similar for the next one
> > 
> > Happy eyeballs means that a clients reaction to congestion is
> > to perform an DoS attack, flood the network with additional
> > connection requests and hammer the server with many additional
> > half-open connections that will never actually get used.
> 
> It is not a DoS attack.  The client is almost certainly going to
> make those connection attempts anyway if the path is congested
> enough to cause the first connection attempt to fail.  The only
> difference is the application gives up in 30 seconds rather than
> 60 or 90 seconds by doing the attempts serially.

150...250ms  ?!

For a satellite link you already have started 3 parallel connects
in non-congested(!) situations. 

just some random IPv4 pings from my office (in germany)
_without_congestion_:

   ping  www.asus.com.tw            300-380ms
   ping  south-america.pool.ntp.org 280-370ms
   ping  oceania.pool.ntp.org       340-420ms
   ping  www.eff.org                160-170ms
   ping  www.ietf79.cn              330-450ms
   ping  www.ietf76.jp              270-370ms

So your approach is already hurting the network without congestion!

-Martin