Re: [Isis-wg] Benoit Claise's No Objection on draft-ietf-isis-sbfd-discriminator-02: (with COMMENT)

"Alvaro Retana (aretana)" <aretana@cisco.com> Wed, 18 November 2015 19:48 UTC

Return-Path: <aretana@cisco.com>
X-Original-To: isis-wg@ietfa.amsl.com
Delivered-To: isis-wg@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 806841A912B; Wed, 18 Nov 2015 11:48:39 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -15.086
X-Spam-Level:
X-Spam-Status: No, score=-15.086 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_HI=-5, RP_MATCHES_RCVD=-0.585, SPF_PASS=-0.001, USER_IN_DEF_DKIM_WL=-7.5] 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 y5Cvxh7zC-ok; Wed, 18 Nov 2015 11:48:37 -0800 (PST)
Received: from rcdn-iport-3.cisco.com (rcdn-iport-3.cisco.com [173.37.86.74]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 46EB71A9125; Wed, 18 Nov 2015 11:48:37 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=3743; q=dns/txt; s=iport; t=1447876117; x=1449085717; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-id:content-transfer-encoding: mime-version; bh=KD/Jc2jMkeC/WPVGyzfBP0Wow5ZfnA21ULn+9pD5qvc=; b=gNbXGSZCfBA2+V8cX4wseauyAcoqSpVK5a5nbFK/YThRPMekh+usP19I 4IhP/3bDd+4yMnbtXZ4mo3yx0Wg5CgCAkcEpC/n+WCppK4tc98tngDBpu njH5RG0tlW9u17QFL1HXu5dB+DbMakKsMOFykE+atV8h7ymg8qp2irzKn c=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: A0AnAgDY1ExW/5JdJa1egztTbwa8Q4IaAQ2BZSGFbgKBUDgUAQEBAQEBAYEKhDQBAQEDATo/DAQCAQgRBAEBAR4FCyERHQgCBAENBYgZAwoIDbsGDYRaAQEBAQEBAQEBAQEBAQEBAQEBAQEBFASGVAGEfYJThmYBBJJog2IBizWBdZRyh1IBHwEBQoIRHRaBQHIBhASBBwEBAQ
X-IronPort-AV: E=Sophos;i="5.20,314,1444694400"; d="scan'208";a="51573798"
Received: from rcdn-core-10.cisco.com ([173.37.93.146]) by rcdn-iport-3.cisco.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Nov 2015 19:48:36 +0000
Received: from XCH-RCD-003.cisco.com (xch-rcd-003.cisco.com [173.37.102.13]) by rcdn-core-10.cisco.com (8.14.5/8.14.5) with ESMTP id tAIJmaX0009595 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL); Wed, 18 Nov 2015 19:48:36 GMT
Received: from xch-aln-002.cisco.com (173.36.7.12) by XCH-RCD-003.cisco.com (173.37.102.13) with Microsoft SMTP Server (TLS) id 15.0.1104.5; Wed, 18 Nov 2015 13:48:35 -0600
Received: from xch-aln-002.cisco.com ([173.36.7.12]) by XCH-ALN-002.cisco.com ([173.36.7.12]) with mapi id 15.00.1104.000; Wed, 18 Nov 2015 13:48:35 -0600
From: "Alvaro Retana (aretana)" <aretana@cisco.com>
To: "Les Ginsberg (ginsberg)" <ginsberg@cisco.com>, "Benoit Claise (bclaise)" <bclaise@cisco.com>, The IESG <iesg@ietf.org>
Thread-Topic: [Isis-wg] Benoit Claise's No Objection on draft-ietf-isis-sbfd-discriminator-02: (with COMMENT)
Thread-Index: AQHRIiFB3oT0ZHOz/0u8s9y2YKt7mZ6iDd4wgAAX14D///90oIAAG4gA
Date: Wed, 18 Nov 2015 19:48:35 +0000
Message-ID: <D2723DB9.EAC2B%aretana@cisco.com>
References: <D27211B2.EAB16%aretana@cisco.com> <c415d52120ee46748af281297f64d4fd@XCH-ALN-001.cisco.com> <D27225AB.EABAC%aretana@cisco.com> <55009caae40c46288b235e2b1f7d9691@XCH-ALN-001.cisco.com>
In-Reply-To: <55009caae40c46288b235e2b1f7d9691@XCH-ALN-001.cisco.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-ms-exchange-messagesentrepresentingtype: 1
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [10.117.15.3]
Content-Type: text/plain; charset="us-ascii"
Content-ID: <8F89DCE879D3544AB20E5544D2898B7E@emea.cisco.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Archived-At: <http://mailarchive.ietf.org/arch/msg/isis-wg/8sKWXebAxy20C4_QRH6st61z84w>
Cc: "draft-ietf-isis-sbfd-discriminator@ietf.org" <draft-ietf-isis-sbfd-discriminator@ietf.org>, "isis-wg@ietf.org" <isis-wg@ietf.org>, "chopps@chopps.org" <chopps@chopps.org>, "isis-chairs@ietf.org" <isis-chairs@ietf.org>, "menachemdodge1@gmail.com" <menachemdodge1@gmail.com>
Subject: Re: [Isis-wg] Benoit Claise's No Objection on draft-ietf-isis-sbfd-discriminator-02: (with COMMENT)
X-BeenThere: isis-wg@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: IETF IS-IS working group <isis-wg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/isis-wg>, <mailto:isis-wg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/isis-wg/>
List-Post: <mailto:isis-wg@ietf.org>
List-Help: <mailto:isis-wg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/isis-wg>, <mailto:isis-wg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 18 Nov 2015 19:48:39 -0000

On 11/18/15, 2:27 PM, "Les Ginsberg (ginsberg)" <ginsberg@cisco.com> wrote:

Les:

>I think you are referring to this text from
>https://www.ietf.org/id/draft-ietf-bfd-seamless-base-05.txt
>
>Section 3

Yes, that's what I quoted below (and in the DISCUSS itself).

>
>"...Allocated S-BFD discriminators may be advertised by
>   applications (e.g., OSPF/IS-IS)."

The next sentence says:  "Required result is that applications, on other
network nodes, possess the knowledge of the mapping from remote entities
to S-BFD discriminators."


>This is (in my view) poorly worded bordering on inaccurate.

At the very least the text is confusing.  I think you can interpret it
either way.


>In the context of the IS-IS/OSPF drafts we are defining a way to
>advertise the S-BFD Discriminator(s) assigned to a given node. This does
>not imply any usage of these values by the IGPs.
>
>It is conceivable that the IGPs could find a use for an S-BFD session and
>in that context the IGPs would be an S-BFD client and considered an
>"S-BFD application". But that is NOT what is covered in the current IGP
>drafts - nor is it within scope.
>So I reiterate, the current discussion regarding how applications decide
>which S-BFD discriminator should be used is out of scope for the existing
>IGP drafts.
>
>The entire discussion belongs in the BFD WG.

Agreed, the discussion should be there.  I have asked the Chairs to lead
that discussion (while keeping everyone else in the loop: isis, ospf,
l2tpext).

There is nothing specified in an S-BFD document that talks about the
mapping topic (except for the text above).  As I said below, it worries me
that S-BFD is expecting the "applications" (yes, the draft could've
probably used a better word and not lumped the IGPs in there...but it did)
to do something that is not being done.

Alvaro.


 
> 
>
>   Les
>
>
>> -----Original Message-----
>> From: Alvaro Retana (aretana)
>> Sent: Wednesday, November 18, 2015 10:12 AM
>> To: Les Ginsberg (ginsberg); Benoit Claise (bclaise); The IESG
>> Cc: draft-ietf-isis-sbfd-discriminator@ietf.org; chopps@chopps.org;
>> menachemdodge1@gmail.com; isis-chairs@ietf.org; isis-wg@ietf.org
>> Subject: Re: [Isis-wg] Benoit Claise's No Objection on
>>draft-ietf-isis-sbfd-
>> discriminator-02: (with COMMENT)
>> 
>> On 11/18/15, 12:47 PM, "Les Ginsberg (ginsberg)" <ginsberg@cisco.com>
>> wrote:
>> 
>> Les:
>> 
>> >Neither IS-IS nor OSPF are the "application" here. We are simply the
>> >transport for an opaque piece of information. It makes no sense to me
>> >to ask the IGPs to clarify what is an issue between S-BFD and an
>>application.
>> 
>> What you say makes sense.
>> 
>> It also makes sense to me that one could argue that since we're
>>transporting
>> opaque information we could also include an extra piece of opaque
>> information to let someone else know what the first piece was for.
>> Note that I'm offering that scenario just as an example of the fact
>>that there
>> are at least a couple of potential interpretations.
>> 
>> Because of the language used in the Base S-BFD draft (where it does call
>> OSPF/IS-IS an "application", [1]), I just want to play it safe and make
>>sure
>> we're not pointing at each other and that result won't be that no one
>>does
>> the mapping.
>> 
>> Thanks!
>> 
>> Alvaro.
>> 
>> 
>> [1]
>> 
>>    session.  Allocated S-BFD discriminators may be advertised by
>>    applications (e.g., OSPF/IS-IS).  Required result is that
>>    applications, on other network nodes, possess the knowledge of the
>>    mapping from remote entities to S-BFD discriminators.  The reflector
>> 
>