By Kimberly B. Caisse, Network World -- Network administrators at Liberty Medical Supply, a Medicare provider of diabetes products and medications, had no qualms about using 10G Ethernet to handle data traffic between the company's facilities spread across several miles in Port St. Lucie, Fla. "We have a SONET DS-3 [connection], but it doesn't really fit the bill for data, and we couldn't use it for SAN traffic," says network manager Hal Marietta. A DS-3 was too slow to handle Liberty's data traffic. Liberty Medical just opened a third building last month. When IT made the decision to move from SONET, the company linked its headquarters and the new warehouse using two Extreme Networks' BlackDiamond switches equipped with WDMi (wave division multiplexing with Extreme's Layer 3 Summit "i" chipset) blades. A BlackDiamond 6816 sits at headquarters, while a 6808 is deployed in the data center of the warehouse campus. Liberty Medical leases dark fiber from BellSouth to carry the traffic, but also keeps a DS-3 line to use as a backup. The 10G Ethernet interfaces are split based on Liberty Medical's service needs, Marietta says. At the moment, 2G bit/sec is dedicated to running the storage-area network (SAN) and another gigabit is used to transmit regular data between the buildings. "Did we need the 10Gig now? No. But we may in the future," he says. An application Liberty Medical might use is direct video to the desktop. The 10G Ethernet network can support that bandwidth expansion, Marietta says. "We would have been hard pressed to meet our needs without this option, both presently and going forward," he says. Although Marietta doesn't want to disclose what Liberty Medical paid for the 6808 and 6816 boxes, he expects to see a return on investment in less than two years. Pricing for the BlackDiamond 6800 series starts at $21,985 for the basic six-slot configuration, while the WDMi interface is $60,000. On the West Coast, the University of Southern California Information Sciences Institute recently upgraded the Gigabit Ethernet interfaces on its Foundry Networks' BigIron Layer 3 switches to 10G Ethernet, according to Richard Nelson, director of ISI's information processing center. The ISI, which is researching bandwidth-intensive grid computing, is part of a small WAN that links it to USC and the One Wilshire Building collocation facility in Los Angeles. The ISI first wanted Gigabit Ethernet because it's less expensive per port than its previous packet-over-SONET (POS) gear. High-speed Ethernet generally runs one-tenth to one-fifth the cost of POS. But the price difference between Gigabit and 10G Ethernet ports is nothing to sneeze at. According to Seamus Crehan, a senior analyst at Dell'Oro Group, a Layer 3 gigabit port for a modular fiber connection costs about $1,300, while one 10G Ethernet port costs about $30,000. Prices of 10G Ethernet network interface cards (NIC) likely will fall during the next five years, which is when Dell'Oro Group expects sales volumes to start increasing. Dell'Oro estimates that 10G Ethernet will cost about $6,700 per port in 2005. As 10G Ethernet gears up to storm MANs and WANs, engineers will be working on its current technological limitations. Ethernet's most serious problem in MAN and WAN applications is that it doesn't have the reliability, resiliency and redundancy of SONET, which has a 50-millisecond failover rate. The Spanning Tree Protocol aims to improve Ethernet's failure-and-recovery times to between 3 and 30 seconds, as does Resilient Packet Ring technology. Ethernet also still needs to support TDM, which lets telephone companies transmit digital signals on their long-distance trunks. It also is hard to manage because network administrators can't find faults and performance problems in an Ethernet WAN, says David Passmore, research director at Burton Group. Ethernet's limited reach has become less of a problem now that the 802.3ae standard is in place. The standard outlines distance maximums -- 1.24 miles for short-reach, 6.2 miles for medium-reach and 24.8 miles for long-reach applications -- for single-mode fiber. The distance is more limited for 10G Ethernet that runs on multimode fiber. The WAN-PHY of 10G Ethernet uses SONET framing, which will let the technology utilize SONET amplifiers and repeaters to get around the distance issue in the WAN. Regardless of the drawbacks, carrier start-ups like Yipes Enterprise Service, OnFiber Communications and Cogent Communications along with some incumbent local exchange carriers (ILEC) plan to offer Ethernet WAN services. None are offering 10G Ethernet service yet. "There are [requests for proposal] on the street," Passmore says. "[The ILECs] just haven't moved very aggressively yet." In the enterprise, the use of Gigabit Ethernet NICs in laptop computers "is putting pressure on wiring closet switches to upgrade to 10 Gigabit Ethernet," he adds. Storage backup is another enterprise function that cries out for more bandwidth. "You need 1G to do this in a reasonable time frame." To prepare for 10G Ethernet, think about your cabling. 10G is optimized to run on single-mode fiber, says Bruce Tolley, senior product line manager for emerging technologies at Cisco. He estimates that 90% of companies use multimode fiber. "We have the ability in the standard to support multimode fiber, but it's not clear when we'll get those parts at reasonable prices," Tolley says. However, more companies will upgrade to single-mode fiber because the fiber infrastructure inside buildings is considered a 10- to 12-year investment, he says. With companies priming their network infrastructure for 10G Ethernet and engineers making it more robust, Ethernet's movement into the WAN is gaining speed. Copyright 2002 Network World. Supercomputing Online is a Network World Content Partner.