Re: [TICTOC] EXTERNAL: FW: I-D Action: draft-ietf-tictoc-1588v2-yang-08.txt

Dear Alex,

Thanks for your clarification on this YANG restriction. 
I totally agree with you that "the value of a key in an existing list entry cannot be overwritten. At best the entry can be removed and a new entry with different key values can be added."
This predicate implies that when "port-number" is a key in both list port-ds-list and list transparent-clock-port-ds-list, it is read-only in effect.

Cheers,
Yuanlong

-----Original Message-----
From: Alex Campbell [mailto:Alex.Campbell@Aviatnet.com] 
Sent: Monday, July 02, 2018 1:25 PM
To: Jiangyuanlong <jiangyuanlong@huawei.com>; tictoc@ietf.org
Cc: tictoc-chairs@ietf.org; ZHAO, WILLIAM <william.zhao@siemens.com>; t.petch <ietfc@btconnect.com>; Dave Thaler <dthaler@microsoft.com>
Subject: Re: EXTERNAL: [TICTOC] FW: I-D Action: draft-ietf-tictoc-1588v2-yang-08.txt

> 1. According to IEEE 1588 and per the discussions in the mailing list, we changed two attribute members to "config false" in the YANG module (default-ds. clock-identity and transparent-clock-default-ds. clock-identity), i.e., they are changed to read-only.
> It seems YANG has a requirement that if a leaf key is config false, then its container list must also be config false. Otherwise, the parser will not pass.
> Therefore, key "port-number" in both list port-ds-list and list transparent-clock-port-ds-list remain writable.

I would just like to clarify on the reason for this particular restriction, as the wording of this comment makes me suspect it might not be understood.

Keys' values are used to identify a list entry.
A "config true" list with "config false" keys doesn't seem to make a lot of sense, because it would mean the management station can add an entry, but it can't set the keys, so it can't identify which entry it is adding. At least, that is my interpretation - please correct me if I'm wrong here.

In any case (even with "config true") the value of a key in an existing list entry cannot be overwritten. At best the entry can be removed and a new entry with different key values can be added.

Regards,
  Alex

________________________________________
From: TICTOC <tictoc-bounces@ietf.org> on behalf of Jiangyuanlong <jiangyuanlong@huawei.com>
Sent: Monday, 2 July 2018 3:50 p.m.
To: tictoc@ietf.org
Cc: tictoc-chairs@ietf.org; ZHAO, WILLIAM; t.petch; Dave Thaler
Subject: EXTERNAL: [TICTOC] FW:  I-D Action: draft-ietf-tictoc-1588v2-yang-08.txt

Hi experts,

As there have been quite a few comments raised during the Last Call process and in the Intdir early review stage, we have produced this new version with all the suggestions and resolutions incorporated.
A summary of the changes introduced in this document:
1. According to IEEE 1588 and per the discussions in the mailing list, we changed two attribute members to "config false" in the YANG module (default-ds. clock-identity and transparent-clock-default-ds. clock-identity), i.e., they are changed to read-only.
It seems YANG has a requirement that if a leaf key is config false, then its container list must also be config false. Otherwise, the parser will not pass.
Therefore, key "port-number" in both list port-ds-list and list transparent-clock-port-ds-list remain writable.

2. As noted in the mailing list, leaf member "clock-identity" is removed from transparent-clock-port-ds-list (since portIdentity.clockIdentity is already provided as the clock-identity leaf in transparent-clock-default-ds).

3.The last paragraph of Section 2.2 is updated to: "Under certain circumstances, the classification of an IEEE 1588 data set member may change for a YANG implementation, for example, a configurable member needs to be changed to read-only. In such a case, an implementation MAY choose to return a warning upon writing to a read-only member, or use the deviation mechanism to develop a new deviation model as described in Section 7.20.3 of [RFC7950]." We hope the new texts make it clear how an implementer may change the behavior of YANG attributes in practice.

4. we added references to [IEEE1588] for terms BC, OC and TC as commented by Dave.

5. RFC7950 is added as a normative reference; since two RFC references are obsoleted, we updated them with their newest version (i.e., RFC 8341 and RFC 8343).

6. we add editorial improvements as our reviewers proposed, and use RFC2119 key words in several sentences in Section 1 and Section 2.2.

In fact, the main technical changes were already presented in the last IETF meeting, the new changes are mostly editorial.
Thanks a lot to our reviewers! Further reviews and opinions will be appreciated.

Thanks,
Yuanlong on behalf of all co-authors

-----Original Message-----
From: TICTOC [mailto:tictoc-bounces@ietf.org] On Behalf Of internet-drafts@ietf.org
Sent: Monday, July 02, 2018 10:52 AM
To: i-d-announce@ietf.org
Cc: tictoc@ietf.org
Subject: [TICTOC] I-D Action: draft-ietf-tictoc-1588v2-yang-08.txt

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Timing over IP Connection and Transfer of Clock WG of the IETF.

        Title           : YANG Data Model for IEEE 1588-2008
        Authors         : Yuanlong Jiang
                          Xian Liu
                          Jinchun Xu
                          Rodney Cummings
        Filename        : draft-ietf-tictoc-1588v2-yang-08.txt
        Pages           : 30
        Date            : 2018-07-01

Abstract:
   This document defines a YANG data model for the configuration of
   IEEE 1588-2008 devices and clocks, and also retrieval of the
   configuration information, data set and running states of IEEE
   1588-2008 clocks.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-ietf-tictoc-1588v2-yang/

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-ietf-tictoc-1588v2-yang-08
https://datatracker.ietf.org/doc/html/draft-ietf-tictoc-1588v2-yang-08

A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-ietf-tictoc-1588v2-yang-08

Please note that it may take a couple of minutes from the time of submission until the htmlized version and diff are available at tools.ietf.org.

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

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