IETF Logo Mail Archive

Re: [Lsr] A new version of I-D, draft-liu-lsr-isis-ifit-node-capability-02

tony.li@tony.li Thu, 02 April 2020 23:44 UTC

Return-Path: <tony1athome@gmail.com>
X-Original-To: lsr@ietfa.amsl.com
Delivered-To: lsr@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 25C023A044E for <lsr@ietfa.amsl.com>; Thu, 2 Apr 2020 16:44:07 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.736
X-Spam-Level:
X-Spam-Status: No, score=-1.736 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.001, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, HTML_MESSAGE=0.001, SPF_HELO_NONE=0.001, T_SPF_TEMPERROR=0.01] autolearn=no autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
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 MNrgBbShL1PB for <lsr@ietfa.amsl.com>; Thu, 2 Apr 2020 16:43:54 -0700 (PDT)
Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id C9FFB3A0486 for <lsr@ietf.org>; Thu, 2 Apr 2020 16:43:34 -0700 (PDT)
Received: by mail-pf1-x42d.google.com with SMTP id c20so2551726pfi.7 for <lsr@ietf.org>; Thu, 02 Apr 2020 16:43:34 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:message-id:mime-version:subject:date:in-reply-to:cc:to :references; bh=n+EOXNNXEgEhtO6WNA7DnOfHj+W4U+y0g5CF7YXkwhk=; b=V1hYY6DhekUNpPFwRO/aqhy/8FxaNs5yLm/RYk2l7dVpXQflKsQGNO4/gdk4G6B8xs MWnn+jLykbDZU244J7PHCP2O018mGmV8QtFQRBZykGgW9uf3nWq6cwvguRKi9KfTPjh3 8E1LhyomXGWKklw4DPov324wHd+dNCOD9ZwvyTcDtlK2U5aNs/dEDgr/+SnYnrbTpkVB IK1cp2XL333rluQ6e03LCI+jdQiw4Kx0At7Pc5YZVIzHtDycUwn/2UEalsXPpMEAOhsw fQdLk67uhg6TMQt+97lvH6u7dMjHkPhs0FSRIKzEpwgZ88FYCMAgfHYgXSdySxmJzFCx oS1A==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:message-id:mime-version:subject:date :in-reply-to:cc:to:references; bh=n+EOXNNXEgEhtO6WNA7DnOfHj+W4U+y0g5CF7YXkwhk=; b=sW0zHHoe4RwpGfzgel37xp36q3xPrG6zM+V6MGZDbgY5RNNyhRVZuMlwZNdhYJaEdp bGh5VKfGIzRwcJcnN3/0oiZb+gIy8zcL3pqDL9TdQ83zWxAV6juQNi8SAh6nGJL9SQvp JhtGkK8SZM3phOuNBf8SSHZ+lDOBPGzlj6XWFGlE4jhvUHKM6lGFzT8f3MeT2i5LD+vg TPVQngO9V2OJ6+AuCOwcGDqekUsOyZZ7zO5ajv4RUtF5yrg1Nip3CjL3RKX7zpRWJIg6 kEmTinbKGdHtmX3wfWOiBa/uOi3ONQFLl5CnffTKwm/pge5b/1CsjoVDP4fGv2rgj0ne JGXQ==
X-Gm-Message-State: AGi0PubdVpkbiyO+u3Q5bO5QBscxq+XYpoV61MW5sJuuUhKTm+xpndtK 8G+o70NZwHBraBdDyLCvIRM=
X-Google-Smtp-Source: APiQypJ4/M9ctjVuu0Xvt7L/1962daF1CYeAIN4WrO5fOLjQN6FelXn+NeXwwe1cuqF4SYOpjYlcig==
X-Received: by 2002:a63:5406:: with SMTP id i6mr5458762pgb.6.1585871008486; Thu, 02 Apr 2020 16:43:28 -0700 (PDT)
Received: from [10.95.92.219] ([162.210.129.5]) by smtp.gmail.com with ESMTPSA id o12sm4487299pjt.16.2020.04.02.16.43.16 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 02 Apr 2020 16:43:27 -0700 (PDT)
Sender: Tony Li <tony1athome@gmail.com>
From: tony.li@tony.li
Message-Id: <8066331D-A0E9-4155-A7AA-F19DCA713C65@tony.li>
Content-Type: multipart/alternative; boundary="Apple-Mail=_FABF0863-5765-4851-A614-912A4C484B7B"
Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.80.23.2.2\))
Date: Thu, 02 Apr 2020 16:43:04 -0700
In-Reply-To: <CAOj+MMEacTvZ=-6rhFY3yrD=UCYU=vY1Bt2asD=KrvR-et-eQg@mail.gmail.com>
Cc: Greg Mirsky <gregimirsky@gmail.com>, "lsr@ietf.org" <lsr@ietf.org>
To: Robert Raszuk <robert@raszuk.net>
References: <1520992FC97B944A9979C2FC1D7DB0F404DB1AD4@dggeml524-mbx.china.huawei.com> <MW3PR11MB4619925BEF83B0C4512DD284C1C90@MW3PR11MB4619.namprd11.prod.outlook.com> <06e8443210924ac788c40fa15972cbdd@huawei.com> <C987B657-64D1-4C70-B471-ED9F1266B990@cisco.com> <3948044C-0CC9-4AE8-8541-4D23A5DF396E@cisco.com> <1520992FC97B944A9979C2FC1D7DB0F404DF089E@dggeml524-mbx.china.huawei.com> <MW3PR11MB46197F8C43B3200B07641838C1C60@MW3PR11MB4619.namprd11.prod.outlook.com> <CAOj+MMGsVkws0sTw4RRdb_SdWvsuh+2Dxc-upXqT2_pmpO_+Lg@mail.gmail.com> <6930807B-2FF0-4A5C-AD39-D05345C37A5E@chopps.org> <MW3PR11MB461955420610E933ACC44BC4C1C60@MW3PR11MB4619.namprd11.prod.outlook.com> <CAOj+MMHoTbDzZrA1ttPsdD5Tk7TADaR=ex5WGF=6+X3X1utoHg@mail.gmail.com> <bd193457-956c-47b0-a50b-8d1778e8349a@Spark> <CAOj+MMGuRHVoJ3ez4nQ3O87J4U+-+yabYWeA1AEfj1UGAbPp7w@mail.gmail.com> <DD4DAC78-3A51-4E8D-802B-9FB515F86AF1@chopps.org> <CAOj+MMHa4J-619P6TWjSohB4yP3O5VPaq42VuAzNUmzbXsFcfA@mail.gmail.com> <4dcafca3-9211-e185-cd69-609cc6cb606f@joelhalpern.com> <CAOj+MMGSjb2Medd_wkV314pYrm_96GD5urxw5Qs34hMZt5BXMw@mail.gmail.com> <CA+RyBmUOgz9kGEBxZYrd7_ADeFPRiwODxqx3FcjpYYAE6tRwGQ@mail.gmail.com> <CA+RyBmXXpiSZj-0=RC=MqTNZYkPFnWZ6+O0ND7Jj1F7Fyh8Tjw@mail.gmail.com> <CAOj+MMGf9a6c9pNLYc+N14O-p86tty6tCaYcZ8gLEQNY6wv1Xw@mail.gmail.com> <CA+RyBmU-+Yh4nJWRUW5odExZcjthGKiaqO-sREHTxiMMwrRbvA@mail.gmail.com> <CAOj+MMEacTvZ=-6rhFY3yrD=UCYU=vY1Bt2asD=KrvR-et-eQg@mail.gmail.com>
X-Mailer: Apple Mail (2.3608.80.23.2.2)
Archived-At: <https://mailarchive.ietf.org/arch/msg/lsr/9kCyssCkQvKbpGtnx7kLVSuLcWc>
Subject: Re: [Lsr] A new version of I-D, draft-liu-lsr-isis-ifit-node-capability-02
X-BeenThere: lsr@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Link State Routing Working Group <lsr.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/lsr>, <mailto:lsr-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/lsr/>
List-Post: <mailto:lsr@ietf.org>
List-Help: <mailto:lsr-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/lsr>, <mailto:lsr-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 02 Apr 2020 23:44:09 -0000
X-List-Received-Date: Thu, 02 Apr 2020 23:44:09 -0000
X-List-Received-Date: Thu, 02 Apr 2020 23:44:09 -0000

> Sure it is possible to discover if my tailends are capable of handling in band telemetry by off line means. But what I am struggling to see why we allowed so much TE stuff into IGPs and we do not want to make it easier for headends to operate without PCE at all for the purpose of delivering such type of services. 


AFAICT, we put a lot of effort into making headend path computation useful and, for the most part, it was and is not necessary.

Even with legacy mechanisms, people decided that they need global optimization and that head-end path computation was Not That Interesting.

It’s now 20 years later, the network is even more dynamic, the expectations about response time are that much higher, and concerns about link state database stability and scalability have increased.  Modern telemetry is definitely not suitable to be passed in the IGP anymore.  

Thus, it seems like the IGP can provide base topology information and traffic engineering constructs should leverage that and provide an independent telemetry collection plane. Within that plane, telemetry capabilities can and should be confined to the telemetry plane.

As we’ve said many times before: BGP is not a dump truck. Analogously, the IGP isn’t even an SUV.

;-)

Regards,
Tony

v2.23.0 | Report a Bug | By Email