Nortel Networks moved to beef up metro Ethernet networks at the Globalcomm carrier-equipment show in Chicago on Tuesday, rolling out a recently developed technology designed to make them more predictable and scalable.Many service providers have been extending Ethernet from its roots in enterprises out to the city scale, an application called metro Ethernet, especially as a tool for offering business data services on an infrastructure that\u2019s familiar to corporate IT departments. Nortel says its provider backbone transport (PBT)\u00a0technology, first announced last year, gives metro Ethernet the reliability and quality of service needed to deliver real-time services such as voice and video. On Tuesday, the company introduced PBT in a product for the first time. The capability is available now in the Metro Ethernet Routing Switch 8600, and the company is working on putting PBT in the Optical Multiservice Edge (OME) 6500 and other products. It is a software feature that will be offered free as part of the latest version of software for the products.Nortel last month reorganized its metro Ethernet infrastructure organization, one of the healthier parts of its business, amid a drive by new President and Chief Executive Officer Mike Zafirovski to refocus the Brampton, Ontario, company. Traditional Ethernet was designed for data, and packet delivery times vary because the technology can\u2019t send packets on predetermined paths across a network. PBT is an enhancement to Ethernet that lets service providers do just that, according to John Hawkins, marketing manager for carrier Ethernet products at Nortel. The carriers could set up paths across the metro network using multiprotocol label switching, the same system used on longer-distance IP backbone networks, but one that becomes expensive as the number of users and services on the network grows, he said.Carriers get the best of both worlds with PBT, Hawkins said. "They like a very well-behaved, very predictable network, but they love the low cost of Ethernet," he said.PBT is a simple point-to-point tunneling technology and is part of an emerging standard, IEEE 802.1ag, that should be finished next year, he said. When combined with another coming standard, IEEE 802.1ah, it allows metro Ethernet to serve millions of users with multiple services. Network gear from other vendors that complies with those standards will deliver all the capabilities of PBT, Hawkins said. Otherwise, the products will still work as intended but won\u2019t be able to deliver the benefits of PBT, he added.Nortel has also integrated resilient packet ring (RPR) technology into the OME 6500 to help existing optical networks carry metro Ethernet services. RPR is already available in the smaller OME 3500. The company also announced on Tuesday an interface card for the Optical Metro 5200 platform that can transport 10-Gigabit Ethernet as far as 175 kilometers (108 miles), much farther than was previously possible. In addition, the company said it is supporting new standards for Ethernet operations, administration and maintenance in its metro Ethernet products.-Stephen Lawson, IDG News ServiceCheck out our CIO News Alerts and Tech Informer pages for more updated news coverage.