EXTENDING ETHERNET'S REACH

The farm belt is not the first place that comes to mind when thoughts turn to advanced fiber networks. And Rochester Telephone, a small independent telco in north-central Indiana, seems a most unlikely candidate to deploy cutting-edge broadband access technologies.

But Rochester President Alan Terrell has been turning the small town stereotype on its head for some time. His 106-year-old local exchange carrier services an area of only 160 square miles and runs only 8700 access lines. In the last few years, however, Rochester has launched its own ISP, resold long-distance service, experimented with wireless and launched its own facilities-based CLEC that runs video and high-speed Internet services over a fiber-to-the-curb network.

Now Terrell is taking Rochester to the next level: full-blown fiber to the home and business, offering triple-play services including voice over IP, analog video programming and high-speed data. It's a monumental undertaking for a carrier Rochester's size, but Terrell is convinced the investment is worth it. After all, the project will afford Rochester the infrastructure to offer cable programming (allowing it to compete with local provider Comcast) and provide data speeds far exceeding the capabilities of DSL.

But to accomplish its goals, Rochester isn't using one of the ATM-based passive optical networking solutions that dominate the market today. Instead, the carrier is using a technology as old as networking itself: Ethernet.

“We've been looking at fiber to the home for about five years now,” Terrell said. “We think the technology's where it needs to be now for us to do it, and with Ethernet, we'll get both the speed and cost savings we need for it to work.”

Rochester Telephone picked Atlanta-based start-up Wave7 Optics' Last Mile Link architecture for its FTTH deployment. Wave7's solution essentially functions as a gigantic Ethernet network, starting with its mammoth 4-gigabit Ethernet links running from a hub router at the central office to the 10/100BaseT jacks at every subscriber's modem. Wave7 takes advantage of Ethernet's ubiquity and leverages the technology's low cost into a less expensive network architecture. And the vendor believes it will match the deployment costs of any copper or coax triple-play network, but with the distinct advantage of gobs of bandwidth.

“Ethernet was a fairly controversial idea when we first got into it,” said Emmanuel Villa, Wave7's chief marketing officer. “There were quality-of-service issues and cost issues, but we've managed to solve them. In the current environment, it looks like we made the right decision. The implications are fairly obvious. Multilayer switches are all over the place, and every interface at home or in the office is already set up for Ethernet.”

Ethernet is not new to network transport, of course — fast Ethernet, gigabit Ethernet and most recently 10-gigabit Ethernet have worked their way into the metro core. But Ethernet has never been a serious contender in terms of last-mile access for small businesses or residential consumers.

It's an oversight the industry can no longer afford to make. More than 90% of all data traffic originates or terminates as Ethernet traffic, whether it's on the network interface card of a home computer or the server bank of a giant corporation. Furthermore, there are an estimated 350 million Ethernet ports currently in service.

“It's cheaper, it's easier to use — it's the most flexible data technology in the world,” said Matt Squire, chief technology officer of Ethernet solutions provider Hatteras Networks. “Almost every corporate local area network uses Ethernet. It's only logical to extend it to the last mile.”

Hatteras' solution has gone one step further than Wave7's architecture. By using copper plant and next-generation networks, it ships Ethernet directly down the twisted pair in addition to conventional fiber strands. Hatteras calls it Access Class Ethernet and markets the solution as a transitional technology to fiber: Carriers can get faster speeds out of a copper line than a T-1 or standard DSL technologies — up to the full 10Mb/s of the 10baseT Ethernet standard — and extend copper's range to 12,000 feet.

“The ultimate goal is fiber throughout the network,” said Rich Williams, Hatteras' director of marketing. “But let's face it: Full fiber deployments in the last mile are a long way off.”

Ethernet over copper lets carriers give their customers capacity to grow beyond the 1.5 Mb/s of a T-1 line without laying a dedicated fiber line. And when they eventually move to fiber, the Ethernet transmission protocols can go with them, making for a seamless transition, Williams said. Currently, Hatteras is developing its technology exclusively for the small and medium-sized business markets, but the company expects Ethernet over copper to eventually make its way to consumers.

First, the technology needs to prove itself in the business market — just as fast Ethernet and gig-E passed muster in the enterprise market before they reached consumers. But Ethernet as a last-mile technology may still have a way to go. Hatteras is just now trialing its Access Ethernet solution, and last-mile fiber Ethernet players such as Wave7 are still in the nascent commercial stages along with the rest of their FTTH brethren.

Last-mile access platforms that use the technology have hit quality-of-service snags in the past, though Hatteras chalks that up to the fact that most Ethernet access platforms have been built on architectures designed for the LAN, not a sophisticated last-mile solution.

Ethernet's other problem is that it's a data-only transmission technology — although not everyone sees that as a fault. Cogent Communications has built its business model around Ethernet's cheap and abundant data capabilities without the benefit of voice.

Cogent runs native Ethernet through its core network of fiber-linked buildings in metro centers and offloads that traffic onto an 80 Gb/s IP backbone using dense wave division multiplexing with Sonet framing. Cogent's metro networks function essentially as huge corporate LANs, except each individual customer is allotted a dedicated amount of bandwidth. While Cogent first started out offering heaps of bandwidth to large and medium-sized businesses at cut-rate prices, it realized it could essentially offer the same service to small businesses.

“The whole network is standardized over Ethernet,” said Cogent CEO Dave Schaeffer. “So we offer the same service to everybody. We just rate-limit our smaller customers to 500 kb/s and charge accordingly.”

But not every carrier can afford to stick to data exclusively — especially carriers with copper and coax networks. The local exchange carriers need to offer voice, the cable companies need to offer video programming, and both groups want to offer all three.

The problem is that in the past, Ethernet has demonstrated spectral compatibility issues, interfering with other digital signals as well as analog voice traffic traveling over the same line. After all, Ethernet's original LANs weren't designed for voice or the local weather report.

But Ethernet access vendors claim they have most of those issues worked out, and the Institute of Electrical and Electronics Engineers is expected by 2004 to finalize its Long-Reach Ethernet standard, which uses frequency division duplexing to allow POTS, video and Ethernet to coexist peacefully on the same twisted pair.

Whatever Ethernet's former problems, they're being smoothed out by this new wave of vendors developing purpose-built access networks — perhaps just in time.

Not only is Ethernet a familiar and manageable technology to most business IT departments, but its affordability is attracting the attention of a growing number of carriers. Hatteras claims typical Ethernet access solutions can save a carrier 45% of its operations costs per subscriber, while its Ethernet Access solution can save operations expenditures anywhere from 40% to 80% over copper and between 50% and 90% over fiber.

“We thought we'd have to evangelize Ethernet to the carriers, but it turns out they were already on board,” Hatteras' Williams said. “It's what their customers have been asking for.”