Making the case for Ethernet everywhere

By Stephen Hardy

Members of the Metro Ethernet Forum (MEF) have until the 9th of this month to submit their MEF1-compliant products for the organization’s new Carrier Ethernet certification program. The MEF hopes the establishment of a certification program will promote the use of Ethernet as a replacement for SONET/SDH and other Layer 2 protocols from one end of a carrier’s network to the other, long-haul links included. As Ethernet gains quality of service (QoS) support, protection, service management, and other attributes normally associated with the ubiquitous SONET/SDH protocols, advocates such as MEF president Nan Chen and Ethernet pioneer Bob Metcalfe foresee “Ethernet killing SONET,” in Metcalfe’s words. While similar statements were made about Internet protocol (IP) during the optical bubble-and are now given as much credence as anything else uttered at that time-observers believe that Ethernet has a better chance to succeed SONET/SDH than earlier pretenders.

The Carrier Ethernet initiative comprises a manifesto and a catalyst for implementation. The equipment that will launch the age of Ethernet beyond the premises and metro will share five attributes, the MEF decrees: mass scalability of services and bandwidth; 50-msec end-to-end path, aggregated line, and node protection; hard QoS, including support of end-to-end service-level agreements for business, mobile, and residential services; TDM support; and service management capabilities, including fast service creation and delivery of carrier class operations, administration, and maintenance (OAM). Many of these capabilities are based on MEF standards work as well as adoption of various aspects of IEEE 802.1 and Internet Engineering Task Force MPLS standards.

The result, say people like Chen and Metcalfe, is that Ethernet can do just about anything that SONET/SDH can do as well as a few other things that the current optical-network foundation protocols cannot. The latter includes efficient handling of the packet-based services that have begun to dwarf circuit-switched voice when it comes to traffic mix. If Ethernet can provide the resiliency and reliability of SONET/SDH and better handle the services customers want, why not just simplify the network by removing SONET/SDH and working with Ethernet?

One reason carriers may be reluctant to do so is a lack of trust in Ethernet’s new capabilities-or at least a reluctance to trust them as much as they have come to rely on SONET/SDH. The certification program is designed to allay these uncertainties and spark Carrier Ethernet implementation. The first round of conformance testing, scheduled to begin this month at Iometrix’s test laboratories, should result in the issuance of certifications in September. This first round of tests, what the MEF has called a “pilot phase,” is open only to MEF members whose equipment meets the E-Line (point-to-point) and E-LAN (multipoint) service provisions outlined in the organization’s MEF1 specification. The tests will be based on a new specification: MEF9.

Once the first round of testing has been completed, the MEF expects to accept other test labs into the program and open the door for non-MEF members to offer their products for certification. Certification means that the products comply with MEF specifications for Carrier Ethernet equipment within the five areas outlined above. The idea is to enable carriers to buy a piece of Carrier Ethernet equipment and be confident that it will carry the attributes the MEF has prescribed. The organization hopes in fact that certification will become an element of future RFPs.

Carriers have already begun to implement Carrier Ethernet equipment and principles, according to Chen, Metcalfe, and Michael Howard, principal analyst and co-founder at market researcher Infonetics Research (Campbell, CA). Chen and Metcalfe say that SBC will implement Carrier Ethernet principles as part of Project Lightspeed, while Howard points to France Telecom as an early adopter.

In fact, Infonetics estimates that just over $60 million were spent last year on Carrier Ethernet equipment. None of these systems was certified, of course; to arrive at that estimate, Howard reports his company took the MEF definitions (minus scalability-Howard says he could figure out how to measure that) and applied them to existing equipment. He believes the current generation of Carrier Ethernet gear includes all the complete product lines of Atrica and Riverstone, the Alcatel 7450, certain configurations of the Cisco Systems 7600 series, Extreme Networks’ Black Diamond, the Tellabs 8800 series, and such recently announced systems as elements of the Siemens Surpass hiD 6600 series, Foundry Networks’ NetIron IMR 640, and Marconi’s OMS2400.

The general move toward Ethernet services bodes well for the success of the MEF’s Carrier Ethernet initiative, Howard believes. A recent Infonetics survey of carriers determined that 85% of respondents plan to offer packet-based voice services by next January. Meanwhile, virtual LAN, managed data services, and other Ethernet-friendly offerings grow in popularity.

Thus, Ethernet may succeed where IP failed in becoming the next generation optical-network protocol. “Ethernet is the interface that corporations like because all of their LANs are on Ethernet. And so it’s just a natural extension. Why have a different technology if the carrier can offer Ethernet?” Howard says. “The whole network gets simplified, and it’s what customers understand and want.”

Howard doesn’t see SONET/SDH disappearing overnight; he estimates that there are 375,000 SONET or SDH rings worldwide, with carriers creating more each day. Carriers will continue to want to leverage this existing investment. “A lot of carriers already have SONET or SDH networks, and for larger customers it’s easier for them to just connect into it. And that’s what they’ve been doing without the carrier class equipment or even with it in a lot of other cases,” he explains.

But Howard envisions that carriers will develop a “cap and grow” strategy in which SONET/SDH investments taper off and Carrier Ethernet equipment-or purely optical equipment such as WDM systems-become the majority beneficiary of investment. “Farther out-and some carriers are doing this today, certainly-they’re looking at Ethernet, especially with the Carrier Ethernet class products available, to simplify their network and making an Ethernet-over-WDM network,” he says. “So many of the Carrier Ethernet products have WDM boards or interfaces so they can connect directly to each other or tie into an existing WDM metro ring, for example. Or just go point to point if the fiber’s available.”