RE: [Diffserv] [OFFLIST] MPLS+Diffserv(mapping DSCP to EXP)

Shahram Davari <Shahram_Davari@pmc-sierra.com> Tue, 04 February 2003 21:44 UTC

Received: from www1.ietf.org (ietf.org [132.151.1.19] (may be forged)) by ietf.org (8.9.1a/8.9.1a) with ESMTP id QAA05237 for <diffserv-archive@odin.ietf.org>; Tue, 4 Feb 2003 16:44:37 -0500 (EST)
Received: (from mailnull@localhost) by www1.ietf.org (8.11.6/8.11.6) id h14LoG526149 for diffserv-archive@odin.ietf.org; Tue, 4 Feb 2003 16:50:16 -0500
Received: from www1.ietf.org (localhost.localdomain [127.0.0.1]) by www1.ietf.org (8.11.6/8.11.6) with ESMTP id h14LfJJ25710; Tue, 4 Feb 2003 16:41:19 -0500
Received: from ietf.org (odin.ietf.org [132.151.1.176]) by www1.ietf.org (8.11.6/8.11.6) with ESMTP id h14LWBJ24626 for <diffserv@optimus.ietf.org>; Tue, 4 Feb 2003 16:32:11 -0500
Received: from father.pmc-sierra.bc.ca (ietf-mx.ietf.org [132.151.6.1]) by ietf.org (8.9.1a/8.9.1a) with SMTP id QAA04742 for <Diffserv@ietf.org>; Tue, 4 Feb 2003 16:26:01 -0500 (EST)
Received: (qmail 16357 invoked by uid 104); 4 Feb 2003 21:29:38 -0000
Received: from Shahram_Davari@pmc-sierra.com by father by uid 101 with qmail-scanner-1.15 (uvscan: v4.1.40/v4245. Clear:. Processed in 0.459728 secs); 04 Feb 2003 21:29:38 -0000
Received: from unknown (HELO hymir.pmc-sierra.bc.ca) (134.87.114.120) by father.pmc-sierra.bc.ca with SMTP; 4 Feb 2003 21:29:37 -0000
Received: from bby1exi01.pmc-sierra.bc.ca (bby1exi01.pmc-sierra.bc.ca [216.241.231.251]) by hymir.pmc-sierra.bc.ca (jason/8.11.6) with ESMTP id h14LTbf29387; Tue, 4 Feb 2003 13:29:37 -0800 (PST)
Received: by bby1exi01 with Internet Mail Service (5.5.2656.59) id <DCPTXWMC>; Tue, 4 Feb 2003 13:29:36 -0800
Message-ID: <4B6D09F3B826D411A67300D0B706EFDEB03C62@nt-exch-yow.pmc-sierra.bc.ca>
From: Shahram Davari <Shahram_Davari@pmc-sierra.com>
To: "'Mark Duffy'" <mduffy@quarrytech.com>, nerdboy@rediffmail.com, Diffserv@ietf.org
Subject: RE: [Diffserv] [OFFLIST] MPLS+Diffserv(mapping DSCP to EXP)
Date: Tue, 4 Feb 2003 13:29:35 -0800
MIME-Version: 1.0
X-Mailer: Internet Mail Service (5.5.2656.59)
Content-Type: text/plain
Sender: diffserv-admin@ietf.org
Errors-To: diffserv-admin@ietf.org
X-BeenThere: diffserv@ietf.org
X-Mailman-Version: 2.0.12
Precedence: bulk
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/diffserv>, <mailto:diffserv-request@ietf.org?subject=unsubscribe>
List-Id: Diffserv Discussion List <diffserv.ietf.org>
List-Post: <mailto:diffserv@ietf.org>
List-Help: <mailto:diffserv-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/diffserv>, <mailto:diffserv-request@ietf.org?subject=subscribe>

> -----Original Message-----
> From: Mark Duffy [mailto:mduffy@quarrytech.com]
> Sent: Tuesday, February 04, 2003 7:29 AM
> To: nerdboy@rediffmail.com; Diffserv@ietf.org

> >2. Further, since the DSCP  ( pow(2,8) = 256 combinations ) 
> is 8 bits and
> >provides 22 different PHB's(or roughly 7 different classes),
> >      and the EXP is just 3 bits and therefore can provide 
> only upto 8
> >different classes, wouldnt there be loss of info while 
> mapping DSCP->EXP ?
> >

No because in MPLS we do DSCP=> PHB translation and PHB=> EXP+Label encoding. The label gives you the context info, so each label can support up to 8 PHBs. To support all 64 PHBs (which are not defined yet) you need 8 parallel LSPs.


-Shahram
_______________________________________________
diffserv mailing list
diffserv@ietf.org
https://www1.ietf.org/mailman/listinfo/diffserv
Archive: http://www.ietf.org/mail-archive/working-groups/diffserv/current/maillist.html