WHITE PAPER
Guidebook to MEF Certification
www.ixiacom.com
Rev A September 2012, 915-6015-01
2
Table of Contents
Introduction...................................................................................................... 4
Benefits of Certification................................................................................... 7
Overview.......................................................................................................... 7
Equipment Vendor............................................................................................ 7
Service Provider.............................................................................................. 8
Enterprise......................................................................................................... 8
Certification Process........................................................................................ 9
Certification Currently Available...................................................................... 9
Future Certifications.......................................................................................17
Overview.........................................................................................................17
Conclusion.......................................................................................................19
3
Introduction
Ethernet was developed as a local area network (LAN) technology, and was quickly
adopted for its high speed, low latency, and plug-and-play features. Defined as an
international standard by the IEEE 802.3 committee, it has been widely deployed in the
LAN. Since Ethernet provides the lowest cost per bit, there is significant interest in using
Ethernet in other parts of the network. Ethernet has pushed into the metro area networks
(MAN) due to its lower cost and lower complexity than existing technologies such as
SONET/SDH. Although Ethernet usage continues to expand, it is not without challenges.
Until recently, it lacked feature sets such as scalability and reliability that other more
mature MAN technologies addressed.
For example, SONET/SDH can recover from a fault in fewer than 50 milliseconds. The
Metro Ethernet Forum (MEF) was created in an effort to accelerate the development and
adoption of Ethernet as a service-enabling technology. In addition to MAN services, there
was significant interest in using Ethernet as a WAN L2 VPN service. The MEF has helped
to advance this effort by defining Ethernet services and related technical standards.
The MEF is made up of the following components:
Technical Committee
Marketing Committee
Certification Program
Global Interconnect Program
The technical specifications are developed within the Technical Committee and through
the approval process. Once approved, they are assigned a MEF specification number. The
technical work is divided into four areas:
•
Service Area
•
Architecture Area
•
Management Area
•
Test and Measurement Area
Since Ethernet is evolving from a LAN technology to a MAN technology – and now even a
WAN service – it is becoming “Carrier Grade” and is referred to as Carrier Ethernet (CE).
To achieve this status, the MEF has defined five attributes:
Standardized Services
Scalability
Reliability
4
Service Management
Quality of Service (See Figure 1).
Figure 1. MEF Carrier Ethernet Attributes
To address the requirement for standardized services, the MEF has defined the technical
specification MEF 6 (now updated to 6.1) which outlines E-Line (EPL or EVPL), E-LAN and
E-Tree services. Ethernet Private Line (EPL) defines the user network interface (UNI) as
a physical Ethernet port. Ethernet virtual private line (EVPL) defines the UNI as a virtual
(VLAN tagged) interface. E-Line services can be used to replace traditional point-topoint services built by legacy technologies like TDM, SONET/SDH, Frame-Relay, or ATM.
E-LAN services can be used to replace multi-point-to-multi-point services built by legacy
services like SONET/SDH, Frame-Relay, ATM, or as an alternative to L3 based IP/MPLS.
E-Tree is a rooted multipoint, and again replaces services built with legacy technologies.
These new connections are defined as Ethernet virtual connections (EVC). New Carrier
Ethernet services are very attractive to enterprise customers since they are typically
higher speed, lower cost, and more flexible than legacy technologies. They are also
effective for service providers since Ethernet is a less complicated, more cost effective
transport to build services on.
It is important to note that the MEF defines Carrier Ethernet as a service from UNI to
UNI. They do not define “how” a service is built end-to-end. Many networks have legacy
infrastructures in the metro and leverage an IP/MPLS core, so the actual implementation
may be a mix of interworked technologies. A provider may choose to extend MPLS into the
metro and use PWE and VPLS to build CE services. Or, a provider may choose to upgrade
or replace their existing Metro technology (like SONET) with native Ethernet switches (see
Figure 2). MEF 9 specification defines how to test MEF 6 service definitions.
5
Figure 2. Carrier Ethernet Architecture
To address the Quality of Service (QoS) requirement, the MEF has defined the MEF 10
(updated to 10.2) technical specification to use service attributes establishing traffic
classes. This requires IEEE 802.1Q (VLAN) tagging providing use of the priority bits.
Implementing QoS provides the ability to offer service level agreements (SLA) and service
profiles. The service definition can include bandwidth, latency, delay variation (jitter),
frame loss, and other bandwidth related parameters. The MEF 14 specification defines
how to test MEF 10 service attributes.
In addition to technical specifications and implementation agreements, the MEF also
produces abstract test suites. These abstract test suites are written to define the standard
tests for a technical standard. An example is that MEF 9, ATS for Ethernet Services at the
UNI, was written to test the technical specification MEF 6.
6
Currently, there are nine abstract test suites defined and three active certifications:
Abstract Test Suite
Certification
MEF 9 – Abstract Test Suite for Ethernet
Services at the UNI (TS)
Yes, for Vendors and Service Providers
MEF 14 – Abstract Test Suite for Traffic
Management Phase 1 (TS)
Yes, for Vendors and Service Providers
MEF 18 – Abstract Test Suite for CES over
Ethernet (TS)
Yes, for Vendors
MEF 19 – Abstract Test Suite for UNI Type
1 (TS)
Expected in 2011 as a pre-requisite for UNI
Type 2 certification
MEF 21 – UNI Type 2 Test Suite (TS)
Part 1 link OAM
Yes, for Vendors
MEF 24 – UNI Type 2 Test Suite (TS)
Part 2 E-LMI
Expected in 2011 as a part of UNI Type 2
certification
MEF 25 – UNI Type 2 Test Suite (TS)
Part 3 Service OAM
Expected in 2011 as a part of UNI Type 2
certification
Certification for MEF 9, 14, 18 and 21 is performed by Iometrix, the MEF approved testing
lab. Pre-requisites for certification require that a company must be a member in good
standing of the MEF to apply for certification. A technical pre-requisite requires that
equipment operating at the UNI of the service provider network must be MEF certified
equipment. This requirement only applies to equipment operating at the edge of the
service provider network at the point where the provider interfaces with the customer to
deliver the service.
Reference website: http://www.iometrix.com/
Benefits of Certification
Overview
The MEF develops Carrier Ethernet technical specifications and implementation
agreements to promote interoperability and deployment of Carrier Ethernet
worldwide. Since forming in 2001, it has grown to 168 member companies including
telecommunications service providers, cable MSOs, network equipment/software
manufacturers, semiconductors vendors, and testing organizations. The MEF certification
program was launched in 2005 and by July 2010 there are over 150 companies and 750
systems that have been certified. The certification testing is run by the MEF approved
lab, Iometrix, and requires that the company being tested is a MEF member company. The
testing typically takes 2 – 4 days and the company is required to provide a supporting
engineer for the testing.
7
Equipment Vendor
Equipment vendors who achieve MEF certification enjoy the following benefits:
• Provides globally recognized standards that independently validate service
functionality and conformance
•
Reduces testing costs and time-to-market by leveraging a single universally
recognized test and certification process
•
Strengthens product launch by guaranteeing full MEF compliance which
minimizes risk to their customer selecting the product
•
Provides a functional and performance benchmark which in many cases is
required by their customers
Service Provider
Service providers who achieve MEF certification have the following key benefits:
• Provides assurance when choosing vendor equipment that compiles to MEF
specifications
•
Reduces service costs, charges, and time on complex testing between
vendors, especially on global installations
•
Establishes solid foundation for Carrier Ethernet ubiquity and interoperability
•
Removes confusion caused by proprietary service names and overlapping
options
•
Allows customers to specify their service requirements by referencing
independent, international standards
Enterprise
Benefits to the end-user enterprise include:
• Demonstrates that MEF certified equipment and services behave and
perform according to agreed service level specification and known
international standards
8
•
Provides IT departments with the knowledge to make informed decisions at
greatly reduced risks knowing that the products/services have been through
standards based testing
•
Accelerates Carrier Ethernet deployment at reduced cost
•
Provides common terminology to compare services
•
Allows companies to answer “yes” to the question “Are you MEF Certified
Compliant?” – Now a common feature of request for quotations (RFQs) and
request for proposals (RFPs).
Certification Process
Overview
Each MEF certification is the result of a lengthy process. This process starts within the
MEF technical committee, and projects go through the MEF specification process as seen
in Figure 4.
Figure 4.
MEF Specification Process
Once the technical specification is created, a technical or marketing committee
can propose that an abstract test suite (ATS) be defined for certification testing of
a specification. The ATS will then go through the same MEF specification process.
There is currently a new proposal within the MEF that would require a marketing
requirements document to precede any ATS projects to clearly outline the goal
and purpose of the certification process. This is currently a work-in-progress.
After the ATS becomes an official MEF specification, then the official test lab of
the MEF – Iometrix – gets involved. They define detailed test cases based on the
ATS, including specifying the variables and test parameters.
The next phase is pilot testing, also run by Iometrix. This involves:
Building the test bed
•
Performing the first round of pilot testing with MEF member companies
•
Resolving any technical issues or oversights
•
Award ceremony announcing the completion of the pilot phase and the first
group of companies which have successfully completed the testing
•
In the final phase, the full certification program is announced. This includes:
•
Opening up the certification to all MEF member companies
•
Logistical issues are all worked out between the companies and Iometrix
•
Testing – Iometrix performs all testing based on the plan as approved by the
MEF
•
Certification – MEF certificate, test reports, permission to use MEF Certified
Compliant logo, and listing on the certified website listing
9
Figure 5. MEF Certified Compliant Logo
Figure 6. MEF Certification Process
In the full certification phase MEF member companies can contact Iometrix about
the cost and logistics to complete the testing. The testing typically takes 2 to 4
days, depending on what aspects are being certified, and will require support
from an engineer of the requesting company to be onsite. To ensure passing the
certification testing it is highly recommended to review the ATS, the Iometrix test
plan and conduct pre-certification testing in preparation before attempting the
certification test.
Certification Currently Available
Overview
The MEF currently offers four certifications for equipment vendors: MEF 9, 14, 18
and 21. Two certifications are available for service providers: MEF 9 and 14.
MEF 9 - Abstract Test Suite for Ethernet Services at the UNI
Purpose: Defines the test suite for conformance of Ethernet services and
equipment when deployed at the UNI as defined in MEF 6.1
The MEF 9 ATS defines 26 test cases.
10
Figure 7. Test Bed for Ethernet Services at the UNI
Figure 8. Example Test Case from MEF 9 ATS
11
As seen in the example test case, the test case is defined and the results are “pass or fail”.
MEF member companies can then get the documents provided by Iometrix, which
include the Test Configuration Guide and the Test Plan. The Iometrix test plan for MEF 9
expands the 26 test cases in the ATS to 244 test cases, which are run serially during the
certification. The expansion of the test cases is to cover all the variables including EPL,
EVPL, and E-LAN test cases.
It is important to review the Iometrix test plan and perform the testing in-house before
attempting certification.
When testing a service provider, Iometrix has them complete a survey first and only tests
to the specific capabilities of the service – which may not include all 244 test cases. Then,
they deploy test probes to three sites to conduct the testing on a live service.
Figure 9. Example Test Case from MEF 14 A
12
Similar to MEF 9, the test case details are provided and the result is a “pass or fail”. The
primary difference is that the MEF 14 tests are based on service attributes which require
traffic generation and performance testing.
The Iometrix test plan for MEF 14 expands the 10 test cases in the ATS to 183 test cases,
which are run serially during the certification.
For service providers, the same methodology is used from MEF 9. Iometrix has them first
complete a survey, and only tests to the specific capabilities of the service – which may
not include all 183 test cases. Then, they deploy test probes to three sites to conduct the
testing on a live service.
MEF 18 - Abstract Test Suite for CES
Purpose: Specifies testing procedures for pass/fail assessment of conformance with each
of the operating modes as defined in MEF 8
The MEF 18 ATS defines 88 test cases which are divided into mandatory, optional, and
dependent.
Figure 10. Test Bed #1 for MEF 18
13
14
The Iometrix test plan expands the test case count up to 344. The certification is
only available for equipment vendors.
MEF 21- Abstract Test Suite for Link UNI Type 2 – Part 1 Link OAM
Purpose: Executes tests against procedures defined in MEF 21 (Abstract Test Suite
for UNI Type 2 - Part 1 Link OAM) based on standard IEEE 802.3ah, clause 57
The MEF 21 ATS defines 140 test cases for the UNI-C and 140 test cases for the
UNI-N.
Figure 14.
Test Bed for MEF 21 UNI-N Test Cases
15
Figure 15. Example Test Case from MEF 21
16
The Iometrix test plan expands the MEF 21 ATS to 371 test cases.
The certification is currently only available for equipment manufactures.
Future Certifications
Overview
The MEF continues to stay active with the development of Abstract Test Suites and
expanding the certification program. Certification is expected to be approved for:
Certification for UNI Type 2 is currently being defined and expected to begin in
2011. The following components will make up partial or complete certification:
•
MEF 19, UNI Type 1 as a pre-requisite
•
MEF 21, UNI Type 2 part 1: Link OAM – already certification available for this
component
•
MEF 24, UNI Type 2 part 2: Part 2 E-LMI
•
MEF 25, UNI Type 2 part 3: Service OAM
•
There is also likely to be an ENNI Service certification based on MEF 26 in
2011.
Conclusion
With the continued growth in CE products and services, it is clearly one of the
leading technologies available today for enabling network services. The MEF
has helped to accelerate CE adoption through standards and certification. At this
point, it is basically a requirement for equipment vendors to be at least MEF 9
and 14 certified, and many aim to lead the UNI type 2 certification for obvious
differentiation in the marketplace. Service providers also clearly benefit from
standardization and the testing helps them to easily interoperate with other
carriers. Enterprise customers – the end-users of CE services – are still learning
the value of MEF certification and they are including it more frequently as a
requirement from equipment and service providers. All companies interested in CE
are encouraged to learn more about the MEF and join to get more information or
pursue certification.
Reference:
http://www.metroethernetforum.org
http://www.iometrix.com
17
WHITE PAPER
Ixia Worldwide Headquarters
26601 Agoura Rd.
Calabasas, CA 91302
(Toll Free North America)
1.877.367.4942
(Outside North America)
+1.818.871.1800
(Fax) 818.871.1805
Ixia European Headquarters
Ixia Technologies Europe Ltd
Clarion House, Norreys Drive
Maidenhead SL6 4FL
United Kingdom
Sales +44 1628 408750
(Fax) +44 1628 639916
Ixia Asia Pacific Headquarters
21 Serangoon North Avenue 3
#04-01
Singapore 554864
Sales +65.6332.0125
Fax +65.6332.0127
www.ixiacom.com
Rev A September 2012, 915-6015-01