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Report stirs Ethernet vs. SONET debate

By Marguerite Reardon
Network World Optical Networking Newsletter, 09/05/01

Analysts agree that Ethernet has a long journey ahead before it overtakes SONET in metro area networks. But questions about what flavor of Ethernet will prevail, the length of time it will take before it becomes widely deployed and where, are still being hotly debated.

Marian Stasney, senior analyst with The Yankee Group, published a report this month saying that, while service providers are certainly considering Ethernet as a low-cost option for delivering high-speed access in metro networks, actual deployments are still thin on the ground.

" Eventually, Ethernet will take over in metro, " says Stasney. " But [that's] at least seven to 10 years down the road. "

Stasney cites several barriers to widespread deployment of Ethernet in the near term. Although Ethernet equipment is much cheaper to purchase and maintain than SONET gear - thus saving on initial capital expenditures and operational costs - the fiber infrastructure needed to support Ethernet services in the metro is still far from ubiquitous.

Further, metro Ethernet applications like voice-over-IP and storage networking are still immature, making carriers less willing to adopt a pure Ethernet approach in the near future.

" Service providers trying voice-over-IP say that quality varies substantially between vendors' gear, " says Stasney. " I'm not sure end users are comfortable with using pure Ethernet for storage yet, either. Even greenfield Ethernet players are being asked to provide services other than Ethernet to handle these services. "

There is also a tremendous amount of SONET already installed in most carrier networks. Some estimates show that there are at least 100,000 SONET rings operating in the U.S. and possibly twice that number of Synchronous Digital Hierarchy rings operating outside the U.S., according to Michael Howard, co-founder and principal analyst with Infonetics Research.

Both Stasney and Howard agree that cutbacks in capital spending mean service providers won't lay massive quantities of fiber, or rip out older SONET infrastructure, to deploy a technology that may not be able to generate revenue right away.

No hard numbers from the report have been released to the public yet, but Stasney says she is basing her research on conversations with 30 to 40 Ethernet, SONET, resilient packet ring (RPR), and wave division multiplexing equipment vendors, as well as on data that was collected for another Yankee Group report on service providers, which has yet to be published.

Other analysts agree with her basic premise. Chris Nicoll, vice president at Current Analysis and Mark Lutkowitz, VP of optical networking research at Communications Industry Researchers, both say they agree that SONET will continue to dominate the metro for at least the next three to five years.

" This is probably the first time that I can say I agree with Yankee, " says Lutkowitz. " The rate at which SONET gear becomes obsolete is very slow. That stuff will be around for another 30 years. There's no question that SONET is here to stay. "

But Lutkowitz seems a bit leery of the specifics of The Yankee Group report: " Projecting the market seven to 10 years is ridiculous."

Fellow analysts also may quibble with Stasney on another point. She is bullish on the prospect of pure Ethernet eventually becoming the technology du jour in the metro, while others say that some combination of Ethernet over SONET, or even the emerging packet technologies like RPR, will rule.

" It's hard to say which technology will win out, " says Stasney. " RPR will likely be extremely important, but with Ethernet over SONET you lose benefits of both technologies. "

Analysts who disagree point to specific examples to back up their case.

" Ocular Networks and Native Networks, both of which offer Ethernet over SONET, are getting serious attention from service providers, " says Nicoll from Current Analysis. " But companies like Atrica and Extreme Networks, pure Ethernet guys, are finding legacy carriers a harder nut to crack. There aren't that many Cogent Communications or Yipes Communications- type providers out there for them. "