By Gary Kim

In the 14th century, the "ether" was a rarefied element filling the upper regions of space. More recently, in physics, "ether" was an all-pervading, infinitely elastic medium through which radio waves traveled. These days, Ethernet as a carrier offering has left the "rarified" stage and, if not yet "all-pervading," is at least "infinitely elastic."

"It's a growing area of demand," says Andrew Goldsmith, Global Internetworking vice president. Of course, up to this point, "it's really still a building-to-building service, compared to other bandwidth products." That's because, up to this point, Ethernet has been seen as a fiber-based service.

Of course, as with all things Ethernet, that is on the cusp of change as well. "We use wireless to extend our metro optical Ethernet services," says Frank Robles, Neopolitan Networks CEO. And copper-based Ethernet also is feasible, notes Michael Horton, Ceterus Networks vice president.

So far, top buyer verticals include financial, legal, education, software and technology companies, says Scott Boyer, Yipes Enterprise Services vice president. Content companies also have been early adopters, as have been the higher education and hospital segments. For schools, Ethernet helps IT managers centralize servers, so its easier to introduce and support new distance learning applications. For hospitals, medical imaging is a driver.

Data center mirroring, backup and disaster recovery have helped spur adoption recently, although connections between various enterprise locations are a good chunk of the business as well.

And though there's been no stampede to rip out legacy connections such as ATM or frame relay, Ethernet has often been deployed when a new location has to be brought up, and then the change is incremental from there. "People don't have to worry about ordering up that next increment of bandwidth and aren't shoehorned into the T-1/DS-3 scheme," says Boyer.

"By and large, nobody's going to rip out existing infrastructure just to add Ethernet on top," says Greg Wortman, Coriolis Networks vice president. And though point-to-point connections have been where most of the activity has been so far, "point-to-multipoint is where I think the next uptick's going to be," Wortman says.

And it isn't simply in the metro networks where Ethernet has started to appear as a carrier service. "Three months ago, nobody was offering international long-haul Ethernet," says Hunter Newby, telx chief strategy officer. "Today, there are five carriers offering trans-Atlantic Ethernet services." Count Global Crossing among firms that have fired up such offerings.

"We run 10 Mbps Ethernet office-to-office from New York to London for $3,000 a month," says Adrian Hobbins, Exponential-e Ltd. chief technical officer. "We run 100 Mbps for $8,450 a month." The company also offers 10 Mbps connections on a PoP-to-PoP basis for $1,300 a month, Hobbins says. 100 Mbps connects, PoP to PoP, wholesale for $4,680 a month, Hobbins adds.

You can do the financial math. In essence, Exponential-e allows customers to buy 100 Mbps worth of bandwidth, instead of a DS-3 at 45 Mbps or a 10 Mbps connection instead of an E-1 at 2 Mbps. "we're really chasing the E-1 trans-Atlantic market," he says.

Some customers currently buying three E-1s across the Atlantic from New York to London may have all the traffic on a single cable, so Exponential-e offers a route diverse backup. But "the big story is the price point, for people who need Layer 2 services to London," Hobbins says.

Much the same can be said for trans-United States Ethernet long-haul. "Today, you can buy 10 Mbps Ethernet connections from telx to One Wilshire for about $1,000 a month," Newby says.

That's not to say metro or long-haul Ethernet services are on radar screens everywhere. "I don't know that we've sold any yet, but we've quoted it," says Russ McNeill, Texas Lone Star Network (Indatel) general manager. "The industry will evolve in that direction, but keep in mind we are in rural Texas and aren't there, yet."

Undeniably, most of the activity is still in the metro markets, says Jeff MacHaffie, NEON Communications vice president. "There isn't much in the long haul yet."

So far, enterprise buyers have driven the market for Ethernet services, whether purchased in a point-to-point or point-to-multipoint configuration. On the metro side of the market, "we're seeing demand for Ethernet in three main categories: direct Internet access, LAN-to-LAN connections and storage networking or disaster recovery," says Boyd Chastant, OnFiber Communications senior product manager.

But many observers see a natural migration into the broader private line arena as well. "One of the applications coming down the road is Ethernet private line, a low cost, high bandwidth alternative to traditional SONET/SDH services," says Global Crossing senior product marketing manager Steve French.

Of course, most of the long haul Ethernet we've seen so far seems to be running on top of SONET. "Gigabit Ethernet may run over a wavelength, but the lower-rate services typically run over SONET," says Maura Mahoney, NEON Communications marketing strategist.

"A pet peeve of mine is that we spend so much time convincing people that technology is important that we don't see the forest for the trees," says Jamey Heinze, Broadwing Communications director of data services. "Ethernet has become the great equalizer because everybody understands it."

Enterprise information technology staffs like it because it's something they really understand, and the cost per port is so low. There's also a perception that Ethernet transport provides more bang for the buck than the traditional alternatives, in addition to offering greater bandwidth scalability. Even in the metro markets, however, retail Ethernet connections often run over SONET, in large part because the infrastructure is already widely in place, while SONET quality of service and restoration capabilities also come into play.

In the wide area network (WAN), Ethernet also is offered by some providers as a distance-insensitive alternative to traditional private lines, particularly in a point-to-multipoint configuration, where links fan out to regional sites from a data center, for example. Broadwing and XO Communications are two companies offering this sort of service.

It's a concept that might be attractive for international PTTs, for example, that might want to land traffic at an undersea cable head and then fan traffic out to a number of U.S. locations without having to worry excessively about mileage charges. In essence, the whole "tail circuit" from cable head to each enterprise location then becomes a "local loop," at least as far as the PTT is concerned.

In other cases, Ethernet transport is a less-complex, lower-cost way to provide frame relay connections, argues Horton. "If you're running a frame relay connection between two locations, carrying voice and data, and you can replace it with an Ethernet connection with low latency, run over SONET, you don't have to worry about setting up and tearing down private virtual circuits." That should translate into lower network management overhead.

On trans-Atlantic routes, for example, Ethernet is "simpler to provision, faster to provision and offers 10 times the performance for three times the cost," says Horton. The cost advantages get more pronounced as bandwidths climb into the gigabit range as well. "An ATM or private line interface runs $20,000 or better, compared to $6,000 to $7,000 for an Ethernet interface," says Horton.

And though most of the attention has been focused on big pipe applications, at least some providers are seeing quicker adoption of lower-bandwidth connections as well. "We're seeing Ethernet used as a replacement for both frame relay and private line connections to branch offices," says Robles. "People are using it to replace DSL, frame relay, PRIs or ISDN."

Still, local area network connections between different enterprise sites are a major driver for wide area Ethernet services. AT&T's Ethernet Switched Service Metropolitan Area Network, for example, enables high-bandwidth (up to one gigabit) any-to-any local area network (LAN) connectivity between customer locations in 67 metro markets in the U.S. It is available in 90 cities and more than 6,400 office buildings on-net.

The service supports the transport of data, voice and video at speeds of 50 Mbps to 1 Gbps and lets customers connect their LANs. It also offers a "self-healing" option that ensures businesses will have continuous access to critical servers, data and applications.

"AT&T is providing business customers with local access and connectivity solutions that help them optimize the way they use their networks," says Barbara Peda, head of product management and product marketing for AT&T Business. "Unlike other providers, AT&T offers 'dedicated, committed' bandwidth, which means customers get all the bandwidth they pay for," says Peda.

However specialized Ethernet services may have been just several years ago, it's gone mainstream. And while metro services arguably are more prevalent, long haul availability is growing. AT&T, for example, offers metro services running between 50 Mbps and 1 Gbps, in hub and spoke, partial mesh and full mesh configurations, at about 6,400 building sites.

AT&T also offers Ethernet running on top of SONET rings and as a long haul product, in both private line and Internet access configurations. Can Ethernet over IP-VPN (virtual private network) and Ethernet over ATM or frame relay be far away? Dagda Mor thinks not.

Both Sprint and Level 3 Communications offer long haul Ethernet-based IP-VPN services. Level 3, for its part, emphasizes the ability to support multiple virtual connections and classes of service in a single interface, says Heather Shepardson, Level 3 director. "If you have a multi-site network, you can run both time-sensitive and time-insensitive applications through the one port, so you have one local loop, not two," she says.

Sprint's Local Telecom Division also offers metro services in 10 Mbps, 100 Mbps and 1 Gbps bandwidths, in ring and point-to-point configurations. Sprint's Global Markets Group is aiming for services similar to LTD's offerings in 12 to 15 major markets, in point-to-point, any-to-any and Internet access versions.

MCI's Ethernet private line service seems primarily oriented toward enterprises everywhere that MCI has local access assets, with an Internet access Ethernet available in some tier 1 cities. The private line service is available in at least 83 markets, at 50 Mbps, 155 Mbps and 622 Mbps bandwidths. The Internet access service runs between 1 Mbps and 600 Mbps, in five or so of the largest markets.

NEON offers point-to-point Ethernet connections at either 50 Mbps or 100 Mbps, in both long haul and metro flavors.

BellSouth customers using OC-48 and OC-192 SMARTRing and LightGate services now have access to 1,000 Mbps Ethernet services. Wavelength services and 10/100 Mbps Ethernet services will be added next year. So far, media and content companies, financial, government, Internet service providers, education and medical verticals have responded.

SBC offers a point-to-point, 1 Gbps service, obviously appealing primarily to larger enterprises, and has added a switched offering as well. Qwest Communications encapsulates Ethernet over ATM, in 2 Mbps up to 1 Gbps bandwidths.

Verizon offers point-to-point services across 19 states and any-to-any services in four states, in 10 Mbps, 100 Mbps and 1 Gbps flavors.

Global Crossing, for its part, now offers a 10 Gbps Ethernet service for intra-European traffic and has added metro Gigabit Ethernet and Fast Ethernet access to its IP transit customers in London.

XO Communications offers frame relay and Ethernet long haul services, encapsulated over its IP network, using mulit-protocol label switching. In the metro, XO offers service at 10 Mbps, 100 Mbps and 1 Gbps, typically running Ethernet over SONET for the Mbps services and over wavelengths for the Gigabit service.

Cogent, unlike some of the other service providers, offers a flat-rate Ethernet service aimed at small and medium-sized businesses, rather than enterprises. The 100 Mbps and 1 Gbps offerings have been broadened to include a 500 kbps service as well, in part to compete with digital subscriber line offerings.

Time Warner Telecom offers point-to-point and any-to-any services in 10 Mbps, 100 Mbps, 1 Gbps and 10 Gbps flavors. The Internet access services is offered in bandwidths from 1 to 2 Gbps in increments of 2 Mbps or more.

Ethernet is coming to the public networks. "But it doesn't completely replace all other forms of transport," says Patrick Coughlin, NEON Communications sales director. "People like the pricing and flexibility, but you aren't going to get SONET levels of protection."

Still, enterprise customers are going to keep asking for it, because it simplifies life and reduces the cost of adding additional hardware and network cards, for example. "The biggest driver probably isn't the bandwidth per se but all the infrastructure and support costs enterprises can reduce," says Matt Porterfield, Lightcore senior vice president.

Carriers without lots of investment in legacy protocols are going to like it for many of the same reasons. "I'd love to be able to give everybody a 1,000 Mbps connection and then let the customer scale bandwidth as they need it, without me rolling a truck all the time," says Porterfield. "Punching down cards, designing circuits and moving jumpers are all the unseen parts of providing bandwidth services to enterprises, and Ethernet is a real cost saver."

Ethernet is anything but ethereal these days.