From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from toronto053.server4you.de ([62.75.220.53]:44490 "EHLO toronto053.server4you.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750889AbYHSOKs (ORCPT ); Tue, 19 Aug 2008 10:10:48 -0400 Date: Tue, 19 Aug 2008 16:10:46 +0200 From: Daniel Wagner To: Johannes Berg Cc: linux-wireless@vger.kernel.org Subject: Re: [PATCH] Use only precedence level of DSCP field for frame classification Message-ID: <20080819141046.GA5946@notlob.celestrius.com> (sfid-20080819_161051_733274_F105F5B4) References: <48AA887D.5090307@monom.org> <48AA8E2C.4060303@monom.org> <48AAAD30.2080207@monom.org> <48AAB70A.4090402@monom.org> <20080819134435.GB11660@notlob.celestrius.com> <1219154378.3476.6.camel@johannes.berg> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1219154378.3476.6.camel@johannes.berg> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, Aug 19, 2008 at 03:59:38PM +0200, Johannes Berg wrote: > On Tue, 2008-08-19 at 15:44 +0200, Daniel Wagner wrote: > > Bit 4-5 of DSCP should not be considered by classify_d1. The > > 802.11 QoS Priority field is only depending on the precedence level. > > Mind explaining a bit more? I don't even know what DSCP really is, any > good reference? Sure. Cisco has a nice summery: http://www.cisco.com/en/US/tech/tk543/tk757/technologies_tech_note09186a00800949f2.shtml In short DSCP supercedes the 'Type of Service' field in the IP header. It is backwarts compatible, that means prescedence field in TOS maps to the DSCP precedence level. The current code checks if the other bits of the TOS are all zero. This ok for configuration which do only set the precedence level. But RFC 2598 introduces the Expeddited Forwarding (EF) which sets some of those lower bits. I think this test is not necessary and in the case for EF even wrong. daniel