IETF Logo Mail Archive

Re: [OSPF] [Isis-wg] Mail regarding draft-ietf-ospf-segment-routing-extensions

Shraddha Hegde <shraddha@juniper.net> Mon, 29 December 2014 10:12 UTC

Return-Path: <shraddha@juniper.net>
X-Original-To: ospf@ietfa.amsl.com
Delivered-To: ospf@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C8BCD1A008B; Mon, 29 Dec 2014 02:12:25 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.902
X-Spam-Level:
X-Spam-Status: No, score=-1.902 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5FFgj7hLweI3; Mon, 29 Dec 2014 02:12:23 -0800 (PST)
Received: from na01-bl2-obe.outbound.protection.outlook.com (mail-bl2on0105.outbound.protection.outlook.com [65.55.169.105]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id C58721A007D; Mon, 29 Dec 2014 02:12:22 -0800 (PST)
Received: from BY1PR0501MB1381.namprd05.prod.outlook.com (25.160.107.139) by BY1PR0501MB1382.namprd05.prod.outlook.com (25.160.107.140) with Microsoft SMTP Server (TLS) id 15.1.49.12; Mon, 29 Dec 2014 10:12:20 +0000
Received: from BY1PR0501MB1381.namprd05.prod.outlook.com ([25.160.107.139]) by BY1PR0501MB1381.namprd05.prod.outlook.com ([25.160.107.139]) with mapi id 15.01.0049.002; Mon, 29 Dec 2014 10:12:20 +0000
From: Shraddha Hegde <shraddha@juniper.net>
To: Rob Shakir <rjs@rob.sh>, Peter Psenak <ppsenak@cisco.com>
Thread-Topic: [Isis-wg] Mail regarding draft-ietf-ospf-segment-routing-extensions
Thread-Index: AdAfZ+2t8gRxJR1gRJOVEF41ljB4rwD1jwiAAAAaeDAAAGH0AAAABIpwAABwSQAAABH9IAAAx7iAAABm0oAAADteMAAA79mAAAC7TkA=
Date: Mon, 29 Dec 2014 10:12:20 +0000
Message-ID: <BY1PR0501MB1381BC773F791EF11B528899D5510@BY1PR0501MB1381.namprd05.prod.outlook.com>
References: <BY1PR0501MB13819883015276791F20D631D5540@BY1PR0501MB1381.namprd05.prod.outlook.com> <54A10B35.4030301@cisco.com> <BY1PR0501MB1381B131A68B321264B7E930D5510@BY1PR0501MB1381.namprd05.prod.outlook.com> <54A10E78.6030006@cisco.com> <BY1PR0501MB1381610E47F46E81528B5416D5510@BY1PR0501MB1381.namprd05.prod.outlook.com> <54A11188.8040301@cisco.com> <BY1PR0501MB1381860D81EE3DF32A76B6D7D5510@BY1PR0501MB1381.namprd05.prod.outlook.com> <54A1173D.6000200@cisco.com> <8673017E-4E86-4D2E-8522-DF49ED869E2D@rob.sh> <BY1PR0501MB13811064F9C6F3FE646CDEBCD5510@BY1PR0501MB1381.namprd05.prod.outlook.com> <EE01350B-D88A-4797-B6D8-8E003405C562@rob.sh>
In-Reply-To: <EE01350B-D88A-4797-B6D8-8E003405C562@rob.sh>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [116.197.184.13]
authentication-results: spf=none (sender IP is ) smtp.mailfrom=shraddha@juniper.net;
x-microsoft-antispam: BCL:0;PCL:0;RULEID:;SRVR:BY1PR0501MB1382;
x-exchange-antispam-report-test: UriScan:;
x-exchange-antispam-report-cfa-test: BCL:0; PCL:0; RULEID:; SRVR:BY1PR0501MB1382;
x-forefront-prvs: 0440AC9990
x-forefront-antispam-report: SFV:NSPM; SFS:(10019020)(6009001)(24454002)(13464003)(51704005)(189002)(377454003)(199003)(99286002)(68736005)(2900100001)(33656002)(31966008)(20776003)(64706001)(46102003)(106356001)(2950100001)(66066001)(102836002)(107046002)(19580405001)(40100003)(62966003)(99396003)(93886004)(54606007)(230783001)(120916001)(74316001)(76576001)(101416001)(86362001)(97736003)(50986999)(2656002)(76176999)(54206007)(92566001)(77156002)(87936001)(122556002)(4396001)(21056001)(19580395003)(54356999); DIR:OUT; SFP:1102; SCL:1; SRVR:BY1PR0501MB1382; H:BY1PR0501MB1381.namprd05.prod.outlook.com; FPR:; SPF:None; MLV:sfv; PTR:InfoNoRecords; MX:1; A:1; LANG:en;
received-spf: None (protection.outlook.com: juniper.net does not designate permitted sender hosts)
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
MIME-Version: 1.0
X-OriginatorOrg: juniper.net
X-MS-Exchange-CrossTenant-originalarrivaltime: 29 Dec 2014 10:12:20.4385 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: bea78b3c-4cdb-4130-854a-1d193232e5f4
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY1PR0501MB1382
Archived-At: http://mailarchive.ietf.org/arch/msg/ospf/HqtG5LMjWRdGyu0vBEscnUU6DN8
Cc: "ospf@ietf.org" <ospf@ietf.org>, "draft-ietf-ospf-segment-routing-extensions@tools.ietf.org" <draft-ietf-ospf-segment-routing-extensions@tools.ietf.org>, "isis-wg@ietf.org" <isis-wg@ietf.org>, "draft-ietf-isis-segment-routing-extensions@tools.ietf.org" <draft-ietf-isis-segment-routing-extensions@tools.ietf.org>
Subject: Re: [OSPF] [Isis-wg] Mail regarding draft-ietf-ospf-segment-routing-extensions
X-BeenThere: ospf@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: The Official IETF OSPG WG Mailing List <ospf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ospf>, <mailto:ospf-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ospf/>
List-Post: <mailto:ospf@ietf.org>
List-Help: <mailto:ospf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ospf>, <mailto:ospf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 29 Dec 2014 10:12:26 -0000

Rob/Peter,


 I think today there are networks which run only on SPF paths and having a facility of "unprotected node-sid" is useful in my opinion 
Rather than not providing such a facility in the protocol at all.

I agree that if there is no sufficient interest on the list it can be dropped. 
I hope we can wait until the holiday season to get over to hear others opinion on this.

Rgds
Shraddha


-----Original Message-----
From: Rob Shakir [mailto:rjs@rob.sh] 
Sent: Monday, December 29, 2014 3:11 PM
To: Shraddha Hegde
Cc: Peter Psenak; draft-ietf-ospf-segment-routing-extensions@tools.ietf.org; draft-ietf-isis-segment-routing-extensions@tools.ietf.org; ospf@ietf.org; isis-wg@ietf.org
Subject: Re: [Isis-wg] Mail regarding draft-ietf-ospf-segment-routing-extensions


> On 29 Dec 2014, at 09:33, Shraddha Hegde <shraddha@juniper.net> wrote:
> 
> <Shraddha> It is likely that some application wants to use the node-sids when the strict path for performance sensitive traffic matches with that of the SPF  for some segments or for the entire path. 
> 

There is nothing stopping it doing so, but it cannot deterministically say that the path will remain coherent with the one that it expects for multiple reasons:

1) Nodes along the path may select a subset of ECMPs, the performance of which may vary.
2) There may be topology changes (triggered by failure or not) which mean that the shortest-path may change.

Given that either of these can result in performance variance, it’s very likely (from a practical standpoint) that the traffic must be able to live with FRRs too - hence it being unclear to me that there’s a requirement for an ‘unprotected’ Node SID.

r.

v2.23.0 | Report a Bug | By Email