[100571] in North American Network Operators' Group
Re: Can P2P applications learn to play fair on networks?
daemon@ATHENA.MIT.EDU (Mikael Abrahamsson)
Fri Oct 26 14:13:00 2007
Date: Fri, 26 Oct 2007 20:12:05 +0200 (CEST)
From: Mikael Abrahamsson <swmike@swm.pp.se>
To: Sean Donelan <sean@donelan.com>
cc: nanog@merit.edu
In-Reply-To: <Pine.GSO.4.64.0710261152120.29812@clifden.donelan.com>
Errors-To: owner-nanog@merit.edu
On Fri, 26 Oct 2007, Sean Donelan wrote:
> If Comcast had used Sandvine's other capabilities to inspect and drop
> particular packets, would that have been more acceptable?
Yes, definately.
> Dropping random packets (i.e. FIFO queue, RED, not good on multiple-flows)
> Dropping particular packets (i.e. AQM, WRED, etc, difficult for multiple
> flows)
> Dropping DSCP marked packets first (i.e. scavenger class requires voluntary
> marking)
> Dropping particular protocols (i.e. ACLs, difficult for dynamic protocols)
Dropping a limited ratio of the packets is acceptable at least to me.
> Sending a TCP RST (i.e. most application protocols respond, easy for
> out-of-band devices)
... but terminating the connection is not. Spoofing packets is not
something an ISP should do. Ever. Dropping and/or delaying packets, yes,
spoofing, no.
> Changing IP headers (i.e. ECN bits, not implemented widely, requires inline
> device)
> Changing TCP headers (i.e. decrease windowsize, requires inline device)
> Changing access speed (i.e. dropping user down to 64Kbps, crushes every
> application)
> Charging for overuse (i.e. more than X Gbps data transferred per time period,
> complaints about extra charges)
> Terminate customers using too much capacity (i.e. move the problem to a
> different provider)
These are all acceptable, where I think the adjust MSS is bordering on
intrusion in customer traffic. An ISP should be in the market of
forwarding packets, not changing them.
--
Mikael Abrahamsson email: swmike@swm.pp.se
