Right on schedule, the MEF today announced a new specification that spells out how network operators will interconnect their Ethernet services so they can offer their customers end-to-end connections more easily and seamlessly. But it also added a new requirement for operators: They need to be bilingual. (See MEF Publishes Ethernet Interconnect Point Agreement .)

The spec, MEF 54, is formally known as the Ethernet Interconnection Point ENNI Implementation Agreement, and it addresses how networks connect Ethernet services using MEF -specified external network-to-network interfaces (ENNIs). But the group of six network operators that came together with the vendors at the UNH-IOL iWarp Testing Consortium over the past year to develop and test MEF 54 also discovered that it wasn't possible to create a way to connect Ethernet services between networks using ENNI and those using a non-standard network-to-network interface (NNI). (See MEF Unites Carriers on Ethernet Interconnect.)

And thus, part of what the MEF is discussing in announcing MEF 54 is the need for network operators to be "bilingual" and support both ways of connecting, says Dan Blemings, director of Ethernet Project Management for AT&T Inc. (NYSE: T), and spokesman for the MEF on the announcement. The MEF is also encouraging network operators to start planning ahead for moving to ENNI adoption, he adds.

"When we went into this project, there was an assumption that maybe there would be a way to get an operator that uses an old non-standard Ethernet interconnection to work with the new types that MEF has specified called an ENNI," Blemings says in an interview with Light Reading. "The testing at UNH revealed that absolutely not, it will not work."

That conclusion was reached after the six operators -- AT&T, CenturyLink Inc. (NYSE: CTL), Frontier Communications Corp. (NYSE: FTR), TelePacific Communications , Verizon Communications Inc. (NYSE: VZ) and Windstream Communications Inc. (Nasdaq: WIN) -- and their vendors had successfully tested interoperability for the most basic of interconnections, an Ethernet Private Line, between operators using ENNIs.

"We started testing NNIs with each other to make sure it would work and that everything was mirroring what was happening in the real world," Blemings explained. "Then we started testing ENNIs together, and we figured out how to make those work, then we purposely did this mixture of one company having an NNI and another an ENNI and categorically across the board, it failed, traffic would not pass."

Operators that move to ENNIs will therefore need to retain the ability to do NNI connections as well, since most network operators connect to a diverse set of other networks, Blemings said. AT&T, for example, connects to about 600 other network operators that border its many service areas.

"Some of those will be NNIs, some will be ENNIs," he says. "If we move to just ENNI, we will stop being able to do business with [network operators that use] NNIs. We will become bilingual, and we will encourage other companies to become bilingual."

The network investment required to get to ENNIs varies by operator and not everyone can make the business case for changing, Bleming says. Network operators with older Ethernet equipment will face higher expenses because much of that will need to be changed out.

"What MEF 54 does is try to arm them with information," he notes. It is then up to the individual operator to determine what their network equipment can support and also what approach the network operators to which they need to connect are taking. One of the original goals of the MEF 54 process was to create a way for network operators to move away from custom NNIs for each interconnection, and encourage them to do that.

So another thing the MEF hopes to accomplish with MEF 54, however, is to encourage network operators who haven't begun their transition to Ethernet and IP to begin that process sooner rather than later, Bleming says. He calls it "a journey" which MEF is encouraging operators globally to start taking, even if it means committing to all new equipment being MEF-compliant.

"They may start it this year, they may start it next year, but at some point, they need to get started," he says. "It make last two years or it may last ten years, but they need to be aware there is this journey, that Ethernet is now the global standard for how companies want to interconnect. Ethernet is rapidly growing and to be part of this global community of Ethernet, they need to be engaged with Ethernet."

Customers will notice the impact of MEF 54 because Ethernet will be available in more places, Blemings says.

It's important for network operators as well, notes Jeff Brown, director of Marketing & Product Management for Windstream. In an interview at the Incompas show, he says this kind of interconnection is critical to be able to add footprint to the network or reach everywhere customers want to go. "Right now, it's difficult because there are a lot of legacy connections that are not MEF-compliant," he says.

Coming shortly will be Phase 2 of the process, which will involve the same players, since they already have equipment in place at UNH-IOL, he adds. This phase will tackle more complex networks designs such as Ethernet virtual private line and E-transit, where traffic is passed from one network through a second one to be terminated on a third.

— Carol Wilson, Editor-at-Large, Light Reading