IETF Logo Mail Archive

Re: [mpls-tp] [PWE3] Proposal of using GAL for PW

Alexander Vainshtein <Alexander.Vainshtein@ecitele.com> Mon, 05 July 2010 12:41 UTC

Return-Path: <Alexander.Vainshtein@ecitele.com>
X-Original-To: mpls-tp@core3.amsl.com
Delivered-To: mpls-tp@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id D472E3A694C; Mon, 5 Jul 2010 05:41:26 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.16
X-Spam-Level:
X-Spam-Status: No, score=-2.16 tagged_above=-999 required=5 tests=[AWL=0.438, BAYES_00=-2.599, HTML_MESSAGE=0.001]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xWGyHCi0R-PG; Mon, 5 Jul 2010 05:41:21 -0700 (PDT)
Received: from ilptbmg01.ecitele.com (ilptbmg01-out.ecitele.com [147.234.242.234]) by core3.amsl.com (Postfix) with ESMTP id F001B3A693A; Mon, 5 Jul 2010 05:41:19 -0700 (PDT)
X-AuditID: 93eaf2e7-b7c13ae0000042a1-51-4c31d2ef8e78
Received: from ilptexch01.ecitele.com ( [172.31.244.40]) by ilptbmg01.ecitele.com (Symantec Brightmail Gateway) with SMTP id 32.13.17057.FE2D13C4; Mon, 5 Jul 2010 15:41:19 +0300 (IDT)
Received: from ILPTMAIL02.ecitele.com ([147.234.244.212]) by ilptexch01.ecitele.com ([172.31.244.40]) with mapi; Mon, 5 Jul 2010 15:41:19 +0300
From: Alexander Vainshtein <Alexander.Vainshtein@ecitele.com>
To: "BUSI, ITALO (ITALO)" <italo.busi@alcatel-lucent.com>
Date: Mon, 5 Jul 2010 15:41:34 +0300
Thread-Topic: [PWE3] [mpls-tp] Proposal of using GAL for PW
Thread-Index: AcsZyGN0IxBPyQW3RsiJBXvOYSLH1gCUsC9QAABmbbAAASc48AAHTcHg
Message-ID: <A3C5DF08D38B6049839A6F553B331C76D37F569BB4@ILPTMAIL02.ecitele.com>
References: <2C2F1EBA8050E74EA81502D5740B4BD6940E809263@SJEXCHCCR02.corp.ad.broadcom.com> <C8529DB4.4489A%giles.heron@gmail.com> <2C2F1EBA8050E74EA81502D5740B4BD6940E80926C@SJEXCHCCR02.corp.ad.broadcom.com> <4C2DB03F.7000709@cisco.com> <15740615FC9674499FBCE797B011623F0B730021@FRMRSSXCHMBSB1.dc-m.alcatel-lucent.com> <A3C5DF08D38B6049839A6F553B331C76D37F569A3D@ILPTMAIL02.ecitele.com> <15740615FC9674499FBCE797B011623F0B730196@FRMRSSXCHMBSB1.dc-m.alcatel-lucent.com>
In-Reply-To: <15740615FC9674499FBCE797B011623F0B730196@FRMRSSXCHMBSB1.dc-m.alcatel-lucent.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
acceptlanguage: en-US
Content-Type: multipart/alternative; boundary="_000_A3C5DF08D38B6049839A6F553B331C76D37F569BB4ILPTMAIL02eci_"
MIME-Version: 1.0
X-CFilter-Loop: Reflected
X-Brightmail-Tracker: AAAAAA==
Cc: "lihan@chinamobile.com" <lihan@chinamobile.com>, "pwe3@ietf.org" <pwe3@ietf.org>, "mpls-tp@ietf.org" <mpls-tp@ietf.org>
Subject: Re: [mpls-tp] [PWE3] Proposal of using GAL for PW
X-BeenThere: mpls-tp@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: MPLS-TP Mailing list <mpls-tp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/mpls-tp>, <mailto:mpls-tp-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/mpls-tp>
List-Post: <mailto:mpls-tp@ietf.org>
List-Help: <mailto:mpls-tp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/mpls-tp>, <mailto:mpls-tp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 05 Jul 2010 12:41:27 -0000

Italo,
Lots of thanks for a prompt response. However, IMHO it is not correct.

E.g., BFD for MPLS LSP (as defined RFC 5884) and BFD in VCCV (as defined in RFC 5885) will provide correct connectivity failure indications regardless of ECMP based on MPLS stack hashing because the same label stack will be used by user traffic and OAM packets.

Do you think I've missed something?

Regards,
     Sasha

From: BUSI, ITALO (ITALO) [mailto:italo.busi@alcatel-lucent.com]
Sent: Monday, July 05, 2010 3:29 PM
To: Alexander Vainshtein; stbryant@cisco.com; Shahram Davari
Cc: lihan@chinamobile.com; pwe3@ietf.org; mpls-tp@ietf.org
Subject: RE: [PWE3] [mpls-tp] Proposal of using GAL for PW

Sasha,

what you say is correct but it is applicable to any environment where you use OAM together with ECMP. I do not see anything specific with GAL and PW.

Italo

________________________________
From: Alexander Vainshtein [mailto:Alexander.Vainshtein@ecitele.com]
Sent: lunedì 5 luglio 2010 10.39
To: BUSI, ITALO (ITALO); stbryant@cisco.com; Shahram Davari
Cc: lihan@chinamobile.com; pwe3@ietf.org; mpls-tp@ietf.org
Subject: RE: [PWE3] [mpls-tp] Proposal of using GAL for PW
Hi all,
IMHO and FWIW, while RFC 5586  (5886 looks like a typo to me) does not place any restrictions on using GAL in non-TP environments, its usefulness in these environments (where various forms of multipath, including usage of entropy labels,  cannot be precluded) for OAM purposes is somewhat problematic:
Adding GAL to the label stack changes this for the multipath mechanisms based on stack hashing, and fate-sharing of OAM and user traffic packets is not guaranteed any more.

My 2c,
     Sasha

From: pwe3-bounces@ietf.org [mailto:pwe3-bounces@ietf.org] On Behalf Of BUSI, ITALO (ITALO)
Sent: Monday, July 05, 2010 11:17 AM
To: stbryant@cisco.com; Shahram Davari
Cc: lihan@chinamobile.com; pwe3@ietf.org; mpls-tp@ietf.org
Subject: Re: [PWE3] [mpls-tp] Proposal of using GAL for PW

I agree with Stewart.

The GAL MUST be at the BoS in MPLS-TP where ECMP is not applicable and entroy labels MUST NOT be used.

In other MPLS environments (e.g., where entropy labels are used), RFC 5886 does not place any restriction on the position of the GAL within the label stack.

Italo

________________________________
From: mpls-tp-bounces@ietf.org [mailto:mpls-tp-bounces@ietf.org] On Behalf Of Stewart Bryant
Sent: venerdì 2 luglio 2010 11.24
To: Shahram Davari
Cc: Andy Malis; mpls-tp@ietf.org; lihan@chinamobile.com; pwe3@ietf.org; HUANG, Feng F (Feng)
Subject: Re: [mpls-tp] [PWE3] Proposal of using GAL for PW
On 01/07/2010 19:35, Shahram Davari wrote:
!mmm so if one used entropy then they can't have OAM?
-SD

Not so. The GAL goes above the entropy label (S=0), so gets parsed first. This works for both PHP and not PHP, and both LSP and PW.

- Stewart

v2.8.7 | Report a Bug | By Email