[99093] in North American Network Operators' Group
Re: Congestion control train-wreck workshop at Stanford: Call for
daemon@ATHENA.MIT.EDU (Sean Donelan)
Wed Sep 5 11:12:11 2007
Date: Wed, 5 Sep 2007 11:01:36 -0400 (EDT)
From: Sean Donelan <sean@donelan.com>
To: Stephen Stuart <stuart@tech.org>
cc: nanog <nanog@merit.edu>
In-Reply-To: <200709051154.l85BsREI029196@nb.tech.org>
Errors-To: owner-nanog@merit.edu
On Wed, 5 Sep 2007, Stephen Stuart wrote:
>> Operators always define the "user" as the person paying the bill. One
>> bill, one user.
>
> It's easy to imagine a context where authentication at the application
> layer determines "user" in a bill-paying context. Passing that
> information into the OS, and having the OS try to schedule fairness
> based on competing applications' "guidance," seems like a level of
> complexity that adds little value over implementing fairness on a
> per-flow basis. In theory, any such notion of "user" is lost once the
> packet gets out on the wire - especially when user is determined by
> application-layer authentication, so I don't consider 802.1X or the
> like to be helpful in this instance.
Money and congestion are aggregated on many different levels. At the dorm
level, money and congestion may be shared on a per-student basis while at
the institution level money and congestion may be shared on a
per-department basis, and on a backbone level money and congestion may be
shared on a per-institution basis.
That's the issue with per-flow sharing, 10 institutions may be sharing a
cost equally but if one student in one department at one institution
generates 95% of the flows should he be able to consume 95% of the
capacity?
>> Its fun to watch network engineers' heads explode.
>
> What if the person paying the bill isn't party to either side of the
> TCP session?
The person paying the bill is frequently not a party to either side of
individual TCP sessions, that is why you also frequently have disputes
over which TCP session should experience what level of congestion.
