LAN services to get new look

Major service providers could begin offering high-bandwidth, low-cost Virtual Private LAN Services next year if the proposed standard for the Ethernet/Multi-protocol Label Switching-based technology is approved by year-end as expected.

Major U.S. carriers including AT&T and MCI are kicking the tires on VPLS - a LAN extension service that supports service-level agreements (SLA) and QoS for individual applications.

AT&T says it is premature to comment in detail but confirms that the company is working on a service, adding that there is no timetable for deployment. MCI says it is looking at a variety of Layer 2 technologies it could add to its existing IP VPN services, including VPLS. Verizon already offers an Ethernet service that runs over its MPLS core network, but it is not based on VPLS. However, Verizon has successfully trialed VPLS in its lab and could offer services based on it within 10 to 24 months, a spokesman says. SBC offers point-to-point Ethernet services now, but by adopting VPLS it also plans to offer point-to-multipoint. Other carriers such as Time Warner already offer VPLS services, and Pennsylvania provider TelCove says it plans to offer them soon.

VPLS is in the final stages of review by the IETF, and once it is approved, equipment vendors such as Alcatel, Cisco, Extreme Networks, Foundry Networks, Juniper and Riverstone Networks that have already produced VPLS gear based on drafts of the standard can work toward interoperability. This is important to carriers that don't want to be locked into buying equipment from a single vendor. Approval is anticipated by early next year at the latest, says Marc Lasserre, co-author of the VPLS proposal and chief scientist for Riverstone.

Once the standard is in place, service providers would consider the technology more seriously as a solid base on which to build new services, says Mark Bieberich, an analyst with The Yankee Group. "You will see some of these Tier 1 service providers commit to VPLS offerings within six to 12 months," he says.

Meanwhile, two smaller U.S. carriers already offer VPLS services, Masergy in Dallas and SureWest in Roseville, Calif. These companies have the advantage of not having existing data service offerings that VPLS would compete against, says Erin Dunn, an analyst with Vertical Systems Group. VPLS doesn't cut into their existing accounts and doesn't require phasing out other technologies such as TDM, frame relay and ATM.

Another drawback for carriers is that the service requires Ethernet connections from customer sites to carrier points of presence, and Ethernet is far from universally available. "The likelihood of finding a service provider with Ethernet access everywhere you need it is unlikely," Dunn says.

Part of the problem is that high-bandwidth Ethernet access requires fiber, and that resource is available mostly in cities. Masergy expands its service area by using devices that carry Ethernet over copper wires instead. Tasman Networks' gear presents customers with two Ethernet ports and can plug into a T-1 or T-3 on the WAN side, running Ethernet over the wire via point-to-point protocol, says Jim Brunetti, Masergy's director of engineering.

Because copper has a slower top speed, using it limits the top speed of Ethernet services that can run over it. On fiber, speeds can reach 1G bit/sec.