Re: [OSPF] draft-kini-ospf-fast-notification-01

András Császár <Andras.Csaszar@ericsson.com> Tue, 05 April 2011 13:07 UTC

Return-Path: <Andras.Csaszar@ericsson.com>
X-Original-To: ospf@core3.amsl.com
Delivered-To: ospf@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id D73C928C102 for <ospf@core3.amsl.com>; Tue, 5 Apr 2011 06:07:13 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -5.527
X-Spam-Level:
X-Spam-Status: No, score=-5.527 tagged_above=-999 required=5 tests=[AWL=0.772, BAYES_00=-2.599, MIME_8BIT_HEADER=0.3, RCVD_IN_DNSWL_MED=-4]
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 OqUdnMRzfCWO for <ospf@core3.amsl.com>; Tue, 5 Apr 2011 06:07:13 -0700 (PDT)
Received: from mailgw9.se.ericsson.net (mailgw9.se.ericsson.net [193.180.251.57]) by core3.amsl.com (Postfix) with ESMTP id 127BF28C101 for <ospf@ietf.org>; Tue, 5 Apr 2011 06:07:12 -0700 (PDT)
X-AuditID: c1b4fb39-b7c6dae0000023f2-d8-4d9b14670e88
Received: from esessmw0184.eemea.ericsson.se (Unknown_Domain [153.88.253.125]) by mailgw9.se.ericsson.net (Symantec Mail Security) with SMTP id CA.CB.09202.7641B9D4; Tue, 5 Apr 2011 15:08:55 +0200 (CEST)
Received: from ESESSCMS0363.eemea.ericsson.se ([169.254.1.133]) by esessmw0184.eemea.ericsson.se ([153.88.115.81]) with mapi; Tue, 5 Apr 2011 15:08:55 +0200
From: =?iso-8859-1?Q?Andr=E1s_Cs=E1sz=E1r?= <Andras.Csaszar@ericsson.com>
To: "Bhatia, Manav (Manav)" <manav.bhatia@alcatel-lucent.com>, "curtis@occnc.com" <curtis@occnc.com>
Date: Tue, 5 Apr 2011 15:08:53 +0200
Thread-Topic: [OSPF] draft-kini-ospf-fast-notification-01
Thread-Index: AcvzOMWKeSZDVLdCRrGNCXiliv07mAADWi0gABK94eA=
Message-ID: <8DCD771BDA4A394E9BCBA8932E83929720E74AF217@ESESSCMS0363.eemea.ericsson.se>
References: Your message of "Tue, 05 Apr 2011 05:29:16 +0530." <7C362EEF9C7896468B36C9B79200D8350CFCF67253@INBANSXCHMBSA1.in.alcatel-lucent.com> <201104050225.p352PaCS029256@harbor.orleans.occnc.com> <7C362EEF9C7896468B36C9B79200D8350CFCF67274@INBANSXCHMBSA1.in.alcatel-lucent.com>
In-Reply-To: <7C362EEF9C7896468B36C9B79200D8350CFCF67274@INBANSXCHMBSA1.in.alcatel-lucent.com>
Accept-Language: hu-HU, en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
acceptlanguage: hu-HU, en-US
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-Brightmail-Tracker: AAAAAA==
Cc: "ospf@ietf.org" <ospf@ietf.org>
Subject: Re: [OSPF] draft-kini-ospf-fast-notification-01
X-BeenThere: ospf@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: The Official IETF OSPG WG Mailing List <ospf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/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: Tue, 05 Apr 2011 13:07:13 -0000

> I believe the idea is quite simple - 
> Flooding a changed LSA in HW (data plane) is faster than 
> doing it in SW (not matter how optimized the latter is) or 
> your control plane.

That's the main purpose, yes.

You could combine this with something else: OSPF could pre-calc/pre-download potential new LSAs to the dataplane anticipating local failures. 

Whenever a local failure really happens, dataplane notices it by LoS or BFD, then can immediately disseminate the changed LSA using FN. So, in addition to the per-hop CP processing of LSAs, you could also spare some time with originating an LSA:
- failure trigger reaching/processed by CP
- OSPF originating a new LSA
- OSPF sending the LSU packet down to DP

Cheers,
András