Liaison statement
Liaison from MEF on IP Service Attributes

We would like to inform you that during our 1Q2016 meeting, MEF has approved a
new project on IP Service Attributes. We have set out some background and
further details below.

MEF is well known for the definition of Carrier Ethernet (CE) services (in MEF
6.2, MEF 33 and MEF 51) based on service attributes (defined in MEF 10.3 and
MEF 26.1). In MEF terms, a "service" refers to the set of attributes and their
values that are agreed between the provider of a serviceand the customer of
that service. These attributes are independent of how the service is
implemented; for example a CE service could be implemented using Provider
Backbone Bridging (802.1Q) or using VPLS (RFC 4761/4762) to provide the
connectivity across the service provider's network. MEF defines both end-to-end
services agreed between a subscriber and a service provider, where the end
points are all User-Network Interfaces (UNIs), and inter-provider services
supplied by one service provider or operator to another, where the end points
may be UNIs or External Network-Network Interfaces (ENNIs).

Note that this differs from how the word "service" is sometimes used in IETF,
e.g. to describe a particular technology (as in "Virtual Private LAN Service").

Although IP Services are widely deployed, there is currently no standard
definition of the attributes and values used to describe them. Each Service
Provider has their own way of describing IP services (including in some cases
their own terminology); this makes it hard for customers to compare service
offerings from different providers, and in particular makes it hard for
providers to interconnect with each other – each Service Provider must form a
specific bilateral agreement with each other Service Provider they wish to
connect with.

Furthermore, there is a desire among service providers to improve service
delivery times by automating the service ordering and configuration process.
This is a key aspect of MEF Lifecycle Services Orchestration (LSO). The aim of
MEF LSO is to deliver the MEF Third Network vision, to provide Assured, Agile
and Orchestrated services. MEF LSO enables automation and orchestration of
service ordering and management between service providers ("East/West
interfaces") through the creation of standard data models and APIs. However, a
pre-requisite for defining those is to have a standard definition of the
service that is to be managed.

The new project is intended to address these issues by providing a standard
definition of IP Services, including both end-to-end services and
inter-provider services, through the definition of a standard set of Service
Attributes that can be used in each case. The scope is limited to IP-VPN and
Internet Access services  (IP peering/transit for internet traffic is
precluded). It is intended that this project is the first step in enabling
multi-operator service orchestration of IP Services using MEF LSO, and that
later projects will use the Service Attributes to create standard data models
and APIs. The intent of LSO is to provide a common framework across different
service technologies; MEF is working with TMF and ONF to create common models
for services, and the standard data models and APIs for IP Services will tie
into this framework.

We have noted that IETF is working on a Yang model for Layer 3 Services in the
L3SM working group. Although the scope of that project in IETF is different, it
is clear there is some synergy between the L3SM work and this MEF project. We
believe that both projects can benefit from input from each other and we hope
to work closely with the L3SM working group to ensure our specifications are
aligned.

The scope of the initial phase of the IP Service Attributes project includes:
-Definition of attributes for IP-capable UNIs and NNIs, for IP Service
connections, and for IP Service End Points at UNIs and ENNIs -IP address
allocations and IP control protocols (e.g. DHCP) etc at UNIs -OAM across the
external interface (by reference to IETF protocols and mechanisms) -Service
Level Specification (SLS) definitions including performance
monitoring/constraints (by reference to IETF protocols and metric definitions)
-Redundant links at an external interface (Subscriber/Service provider or
between Service Providers), including options for different routing protocols.
-Multi-CoS services (i.e. QoS classification) and classification of
Green/Yellow packets including diffserv, Bandwidth profiles, etc. -IPv4, IPv6
and dual stack services -Inter-operator IP-VPN services using options A, B or C
from RFC4364 -Unicast only (multicast is defered to a future phase). -Other
topics may be added as the project progresses.

It is important to note that we intend to make extensive reference to existing
IETF RFCs where applicable; it is not our intent to specify new protocols or
mechanisms where there are existing solutions.

Note: further information about MEF LSO can be found in the LSO Reference
Architecture. The final verison is expected to be published in March; in the
meantime, the latest approved draft is available as below:
https://mef.net/liaison-login Username: mef