Re: [core] Robert Wilton's Discuss on draft-ietf-core-sid-16: (with DISCUSS and COMMENT)

Michael Richardson <mcr+ietf@sandelman.ca> Tue, 13 July 2021 17:38 UTC

Return-Path: <mcr+ietf@sandelman.ca>
X-Original-To: core@ietfa.amsl.com
Delivered-To: core@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1DEF23A10B7; Tue, 13 Jul 2021 10:38:47 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.898
X-Spam-Level:
X-Spam-Status: No, score=-1.898 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
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 yVqX9OOYlrPx; Tue, 13 Jul 2021 10:38:42 -0700 (PDT)
Received: from tuna.sandelman.ca (tuna.sandelman.ca [209.87.249.19]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id E887D3A10B6; Tue, 13 Jul 2021 10:38:41 -0700 (PDT)
Received: from localhost (localhost [127.0.0.1]) by tuna.sandelman.ca (Postfix) with ESMTP id 0310A38B40; Tue, 13 Jul 2021 13:41:34 -0400 (EDT)
Received: from tuna.sandelman.ca ([127.0.0.1]) by localhost (localhost [127.0.0.1]) (amavisd-new, port 10024) with LMTP id R4rgpkXy6zyg; Tue, 13 Jul 2021 13:41:28 -0400 (EDT)
Received: from sandelman.ca (obiwan.sandelman.ca [IPv6:2607:f0b0:f:2::247]) by tuna.sandelman.ca (Postfix) with ESMTP id 9882138B23; Tue, 13 Jul 2021 13:41:28 -0400 (EDT)
Received: from localhost (localhost [IPv6:::1]) by sandelman.ca (Postfix) with ESMTP id E632451E; Tue, 13 Jul 2021 13:38:33 -0400 (EDT)
From: Michael Richardson <mcr+ietf@sandelman.ca>
To: Robert Wilton <rwilton@cisco.com>, The IESG <iesg@ietf.org>, draft-ietf-core-sid@ietf.org, core-chairs@ietf.org, core@ietf.org
In-Reply-To: <162619194652.5730.10916340155265302741@ietfa.amsl.com>
References: <162619194652.5730.10916340155265302741@ietfa.amsl.com>
X-Mailer: MH-E 8.6+git; nmh 1.7+dev; GNU Emacs 26.1
X-Face: $\n1pF)h^`}$H>Hk{L"x@)JS7<%Az}5RyS@k9X%29-lHB$Ti.V>2bi.~ehC0; <'$9xN5Ub# z!G,p`nR&p7Fz@^UXIn156S8.~^@MJ*mMsD7=QFeq%AL4m<nPbLgmtKK-5dC@#:k
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="=-=-="; micalg="pgp-sha512"; protocol="application/pgp-signature"
Date: Tue, 13 Jul 2021 13:38:33 -0400
Message-ID: <26411.1626197913@localhost>
Archived-At: <https://mailarchive.ietf.org/arch/msg/core/v180xd1pSVbkS2wokWpU0G5AQ1Q>
Subject: Re: [core] Robert Wilton's Discuss on draft-ietf-core-sid-16: (with DISCUSS and COMMENT)
X-BeenThere: core@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Constrained RESTful Environments \(CoRE\) Working Group list" <core.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/core>, <mailto:core-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/core/>
List-Post: <mailto:core@ietf.org>
List-Help: <mailto:core-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/core>, <mailto:core-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 13 Jul 2021 17:38:48 -0000

Robert Wilton via Datatracker <noreply@ietf.org> wrote:
    > (1) I would like further discussion regarding whether SIDs are bound just to
    > the schema name, or the schema item definition.

I'm not sure I understand the question.... I guess schema name is the leaf definition.

    > The draft states that if the
    > definition is changed in a non-backwards-compatible (NBC) way then a new SID
    > SHOULD be allocated.

True, I assume that this leads to a new YANG leaf name.

    > But I don't understand how this will work.  Given that
    > the .sid file would then contain exactly the same path but with different sids
    > assigned (for every time the meaning of the definition changes), then how do
    > consumers of the sid file know which sid to use for a given path (given that
    > there is no indication in the .sid file)?  Instead, I think that this is the
    > wrong way to be handling NBC changes, and SIDs should be bound only to the
    > schema path (i.e., the name of the item), and a new SID is only allocated if
    > the name/path changes, and otherwise the same SID is used, even if the
    > definition changes in a non-backwards-compatible way.

This is my understanding.

    > (3) This draft makes use of the rc:yang-data extension.  Was there any
    > discussion about using "YANG Data Structure Extensions" (RFC 8791) instead,
    > which is meant to be a cleaner formulation of the rc:yang-data extension, and
    > without the dependency on RESTCONF?  I would suggest that using RFC 8791 would
    > be preferable if possible.

I don't know of any such discussion, but I don't really understand the distinction.

    > (4) The policy in 7.4.2 for allocation a SID mega-range seems to aiming this
    > towards organizations rather than individuals.

Yes, the idea being that "Zigbee" or "IEEE" or ... would allocate a mega-range.

    > The policy in 7.6 for the "IETF
    > YANG SID Registry" requires an RFC.  What is the mechanism if an individual or
    > open source project wanted to get SIDs assigned for some of their YANG modules?

    > I.e., should we be defining a separate mega-range, managed by IANA, with just
    > Expert Review or Specification Required so that these modules could use SIDs
    > allocated?  Or do you envisage a separate entity taking up the responsibility
    > for coordinating this?

My impression was that there would be a mega-range operated outside of IANA
for this (open source, non-RFC YANG module) kind of thing, but I think that
the energy for doing that may have waned.

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        |    IoT architect   [
]     mcr@sandelman.ca  http://www.sandelman.ca/        |   ruby on rails    [


--
Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
           Sandelman Software Works Inc, Ottawa and Worldwide