Liaison statement
Liaison to IETF on proposed Working Group on L2SM

State Posted
Posted Date 2016-10-31
From Group MEF
From Contact Raghu Ranganathan
To Groups IESG, OPS
To Contacts Benoit Claise
Joel Jaeggli
Response Contact
Purpose For action
Deadline 2017-01-23 Action Needed
Attachments L00254_001_2016Q4-Liaison-IETF-L2SMwg_Ranganath
Liaisons referring to this one Response to your liaison dated 31st October 2016
MEF Forum noticed the announcement of a proposed new L2SM Working Group in
particular, we see the following in the proposed charter:

 - "The model can be used for communication between customers and network
operators, and              to provide input to automated control
      and configuration applications."
 -"Instead, the L2VPN customer service model contains the characteristics of
the service as discussed between the operators and their

We include the following relevant information on MEF published and ongoing
work for your consideration - note in particular that MEF is
already working on Yang modules for MEF services:

1) MEF Service Model & Attributes (Published Specifications)
  - MEF 10.3 Specification
describes Ethernet Service
attributes for services provided to the Subscriber (end user) by the Service
Provider. The Ethernet Services are modeled from the
point of view of the Subscriber’s equipment referred to as the Customer Edge
(CE) that is used to access the service.
        - Note-1: MEF uses 'Subscriber' to refer to user (or Customer) of
Ethernet Services
       -  Note-2: MEF uses 'CE' to refer to Customer Edge for Equipment on the
Subscriber side of UNI (i.e., owned by Subscriber)
  - MEF 6.2 Specification
( focuses
on Ethernet Virtual Connection (EVC) based Ethernet Services offered by a
Service Provider (SP) to a Subscriber.
  - MEF 26.2 Specification
provides the models and framework for interconnecting multiple Carrier
Ethernet Networks (CENs), and the service attributes for services provided by
one Operator to another or to a Service Provider.
  - MEF 51 Specification
( focuses on
Operator Virtual Connection (OVC) based Ethernet Services offered by an
Operator where at least one OVC Endpoint is at an ENNI.

2) MEF Service Information Model (Ongoing Project)
  - MEF has an ongoing project for MEF Carrier Ethernet Services Management
Information Model and has draft approved for final
Letter Ballot (i.e., if successful will be published as MEF 7.3 in January
  - The latest Approved Draft version is available at the liaison login link
provided below.

3) MEF Lifecycle Service Orchestration Reference Architecture (Published
  - MEF 55 Specification
( defines a
reference architecture that describes the functional management entities
needed to support LSO, and the Management Interface Reference Points between
 - MEF's work on Service Information & Data Models can be applicable for the
following interfaces supported by the Service
Orchestration Function (SOF) as shown in Figure 2 of MEF 55 and described in
Section 9.3 of MEF 55:
       - ALLEGRO (CUS:SOF): The Management Interface Reference Point that
allows Customer Application Coordinator
supervision and control of dynamic service behavior (see Section 8.2.3) of the
LSO service capabilities under its purview
through interactions with the Service Orchestration Functionality.
       - LEGATO (BUS:SOF): The Management Interface Reference Point between
the Business Applications and the Service
Orchestration Functionality needed to allow management and operations
interactions supporting LSO connectivity services.
       - INTERLUDE (SOF:SOF): The Management Interface Reference Point that
provides for the coordination of a portion of LSO
services within the partner domain that are managed by a Service Provider’s
Service Orchestration Functionality within the
bounds and policies defined for the service.

4) MEF YANG Modules for MEF Services (Ongoing Project)
  - Please see our previous Liaison to IETF
          -  Jan 2015:
          - Nov 2015: (includes
attachment of the re-scope)
  - Draft YANG Modules are currently being updated to address member comments;
the latest versions are attached and MEF will share the final versions once
they are completed.

Additionally, MEF would like clarification on the proposed charter. For
example, the text in charter includes - "The working group will attempt to
derive a single data model that includes support for point-to-point Virtual
Private Wire Services (VPWS), multipoint Virtual Private LAN services (VPLS)
that use Pseudowires signaled using the Label Distribution Protocol (LDP) and
the Border Gateway Protocol (BGP) as
described in RFC4761 and RFC6624, and Ethernet VPNs specified in RFC 7432." Is
the focus of L2SM about the internal network technologies and implementations
as opposed to "characteristics of the service as discussed between the
operators and their customers"?

Assuming the focus is on the latter, i.e., "characteristics of the service as
discussed between the operators and their customers", we would like to suggest
that, if the working group is approved, IETF proceeds by augmenting the MEF
Yang modules instead of duplicating the work that has already been done in

MEF looks forward to collaborating with IETF to provide the industry with a
single standard Ethernet Service model and related YANG

MEF’s liaison partners may access all MEF approved drafts as follows:
Username: mef
Password: M3F3030
The MEF meets next in Los Angeles, CA, USA on Jan 23-26, 2016.

Attach: mef-service-yang.tar.gz