Subject: [Lime] New Liaison Statement, "Liaison on CFM YANG"

From: Liaison Statement Management Tool <[email-masked]>
Date: Mon, 18 Dec 2017 09:20:23 -0800

Title: Liaison on CFM YANG
Submission Date: 2017-12-18
URL of the IETF Web page: https://datatracker.ietf.org/liaison/1551/

From: Glenn Parsons <[email-masked]>
To: Carlos Pignataro <[email-masked]>,Ron Bonica <[email-masked]>
Cc: Ron Bonica <[email-masked]>,Warren Kumari <[email-masked]>,Carlos Pignataro <[email-masked]>,Layer Independent OAM Management in the Multi-Layer Environment Discussion List <[email-masked]>,Benoit Claise <[email-masked]>,Eric Gray <[email-masked]>
Response Contacts: Paul Nikolich <[email-masked]>,Glen Parsons <[email-masked]>,John Messenger <[email-masked]>
Technical Contacts: 
Purpose: For information

Body: Dear Colleagues, 

Thank you for the information in your liaisons dated May 18, 2017 “Liaison on YANG Model Development” and September 14, 2017 “For Action: YANG model for CFM OAM”, and for your offer to coordinate as IEEE 802.1 seeks to deliver a YANG model for Connectivity Fault Management (CFM, covering OpCode values 0-31 and 96-255) that can serve as the base for BBF, MEF, ITU-T (and other) models pertaining to IEEE Std 802.1Q™-specified CFM. 

We take note of your request for us to provide BBF with a first draft of our P802.1Qcx YANG model. We will act on this request as soon as this draft becomes available. In the meantime, we intend to continue using GitHub (https://github.com/YangModels/yang/tree/master/standard/ieee/802.1) in support of agile and collaborative development of this YANG model. 

We would also like to remind you that P802.1Qcp will serve as a base for P802.1Qcx. The latest P802.1Qcp YANG modules are available on our GitHub repository and are also part of the YANG Catalog (https://www.yangcatalog.org/yang-search/yang_tree.php?module=ieee802-dot1q-bridge). A recent development in P802.1Qcp and, going forward in our other YANG projects, including P802.1Qcx, is that we intend to follow the updated Datastore guidelines produced by the IETF Network Management Datastore Architecture Working Group in https://tools.ietf.org/pdf/draft-ietf-netmod-revised-datastores-03.pdf.  

We would like for P802.1Qcx to meet BBF needs and would therefore appreciate if BBF could provide:
- BBF’s requirements, usage scenarios, and priorities for CFM and its YANG support in P802.1Qcx;
- BBF TR-383a1 models referenced in your latest liaison;
- BBF-identified modifications (bbf2017.305) that would need to be made to MEF 38 and 39 (since P802.1Qcx will also take as input MEF 38 and MEF 39, as well as the corresponding errata that MEF previously identified and communicated to us); and
-BBF’s timeline for completion of the “draft CFM OAM YANG model” you intend to publish.

This should help us better understand the scope of CFM features of interest to BBF as well as how to take your draft CFM OAM YANG model as input to our P802.1Qcx work. 

We are particularly interested in understanding: 
-If BBF requirements cover the whole set or a subset of CFM functionality (e.g., does BBF need support for MIP/MHF creation?); and
-If the use of the “OAM” acronym in your latest liaison means that BBF has requirements beyond those that CFM can meet (e.g., “MIP Identifiers” that are inexistent in IEEE Std 802.1Q).

We noted that, as a rule, BBF makes an effort to reuse YANG models from other organizations. We also noted your intention to ensure that the YANG models, that BBF has under development, remain maximally aligned with P802.1Qcx work. Finally, we noted your description that your shared modules are “specific to access network equipment (e.g., BBF-specified Access Nodes and FTTdp DPUs)”. We take these as indications that you share our interest in avoiding overlap and duplication among YANG modules in the industry. As an example of this interest in IEEE 802.1, at our November 2017 plenary meeting, we decided to widen the applicability of our P802.1Xck YANG model for IEEE Std 802.1X™ Port-Based Network Access Control to (access) interfaces (such as VDSL2) running in “Packet Transfer Mode”. 

As we move forward, we hope we can agree on timelines for our respective projects that minimize overlap and duplication. For example, we are wondering if the publication of your “draft CFM OAM YANG model” could be reprioritized to maximize alignment with P802.1Qcx. At the same time, understanding BBF’s timeline and priorities could potentially allow us to prioritize the development of P802.1Qcx YANG modules based on BBF priorities. 

IEEE 802.1 meets next January 22-26, 2018 in Geneva, Switzerland and March 5-9, 2018 in Rosemont, IL, USA. We also anticipate that a number of IEEE 802.1 participants interested in YANG work will attend the interim meeting that ITU-T Q14/15 is planning to hold Sunday January 28, 2018 to discuss mechanisms to ensure alignment of the IEEE 802 YANG work (P802.1Qcp, P802.1Qcx and P802.3.2 Standard for Ethernet YANG Data Model Definitions) with the Q14/15 Recommendation G.8052.1 “Transport OAM Management Information/Data Models for Transport Ethernet Network Element”. In parallel, IEEE 802 has a YANG interest group called YANGsters set up for discussions (website: http://1.ieee802.org/yangsters/, mailing list: [email-masked], conference calls: 6:00AM PDT the last Wednesday of the month at https://join.me/ieee802.1). We would encourage your participation in those discussions. 

We look forward to continued collaboration on this and other topics. 

Best regards, 
Glenn Parsons 
Chair, IEEE 802.1 WG
Attachments:

    liaision-response-BBF-84-1117-v01
    https://www.ietf.org/lib/dt/documents/LIAISON/liaison-2017-12-18-ieee-802-1-lime-liaison-on-cfm-yang-attachment-1.pdf