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From: "Philip A. Prindeville" <philipp_subx@redfish-solutions•com>
To: David Miller <davem@davemloft•net>
Cc: torsten.schmidt@s2006•tu-chemnitz.de, netdev@vger•kernel.org
Subject: Re: [PATCH] ipv4: add DiffServ priority based routing
Date: Thu, 11 Mar 2010 12:25:24 -0700	[thread overview]
Message-ID: <4B9943A4.8040606@redfish-solutions.com> (raw)
In-Reply-To: <20100112.130355.144803575.davem@davemloft.net>

On 01/12/2010 02:03 PM, David Miller wrote:
> From: "Philip A. Prindeville" <philipp_subx@redfish-solutions•com>
> Date: Tue, 12 Jan 2010 12:59:36 -0800
> 
>> What has changed is how network equipment is required to interpret
>> the meaning of those bits.
>>
>> Even if we pass the bits "as is" to the network, if the network is
>> applying entirely new semantics (and when I say "entirely new", I
>> mean those mandated since 1998), then compatibility in the host
>> kernel API doesn't matter a hoot since the packets will still be
>> handled by every transited router according to the modern semantics.
> 
> People really don't assign global meaning to bits set by applications
> in the TOS field.
> 
> What they do is they have a set of semantics inside of their cloud of
> routers and switch points for diffserv, and when packets come in the
> TOS field is rewritten to whatever scheme is being used inside of that
> cloud.
> 
> And the diffserv bits only have meaning and effect within that cloud.
> 
> So really, having a syscall that sets the TOS bits exactly by
> applications is just fine.
> 
> People are doing diffserv right now with Linux and have done so
> for years.

Sorry about coming back to this weeks later... but I hadn't seen RFC 4594 previously.

What if boxes (i.e. the OS) and applications can preconfigured to use RFC-4594 guidelines by default, and varying from that required the administrator to make specific changes?

I agree with the notion that certain values should be set side-wide (or at least system-wide) to prevent malicious users from exploiting QoS...  that's why I've been advocating for QoS settings to be specified in a system configuration file, and not a per-user configuration file.

-Philip

  parent reply	other threads:[~2010-03-11 19:25 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-12 13:32 [PATCH] ipv4: add DiffServ priority based routing Torsten Schmidt
2010-01-12 20:16 ` David Miller
2010-01-12 20:59   ` Philip A. Prindeville
2010-01-12 21:03     ` David Miller
2010-01-12 21:33       ` Philip A. Prindeville
2010-01-13  4:47         ` Steven Blake
2010-03-11 19:25       ` Philip A. Prindeville [this message]
2010-03-11 19:29         ` David Miller
2010-03-11 19:32           ` Philip A. Prindeville
2010-03-12 11:18           ` Benny Amorsen
2011-02-21  6:01             ` Philip Prindeville
2010-01-14 11:50   ` Torsten Schmidt
2010-01-14 12:50     ` Eric Dumazet
2010-01-15  0:51       ` David Miller
2010-01-15  8:24         ` Eric Dumazet
2010-01-15  8:26           ` David Miller

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