Ethernet has seen off all competitors in companies' local area networks (LANs) -- with the specialised exception of fibre channel -- and is now poised to extend into the service providers' territory. A new telco-friendly version is emerging that will support third-party services, and offer high reliability at a fraction of the cost of existing networks. New Ethernet standards and specifications are virtually complete, and will be finalised in August. "Service providers can do it now," said Nan Chen, president of the Metro Ethernet Forum (MEF). The next area to adopt Ethernet will be metropolitan area (or "metro") networks, which span anywhere from a city to a region as big as some European countries. The MEF's E-Line and E-LAN standards -- currently being voted on -- will allow service providers to adopt Ethernet, said Chen. There is plenty of bandwidth in the long-haul networks between population centres and in LANs, but still a shortage of bandwidth within the metro area. "The last decade has seen LAN capacity expand some 100-fold, and backbone capacity more like 300-fold, while the real bottleneck has been in the metropolitan area, with a bare 16-fold increase," said Chen. Existing metro networks have used Sonet/SDH, an expensive but reliable network designed to carry voice traffic reliably on ring networks. "Until now, metro networking has come at the cost of of a major step change from Ethernet to more expensive, less familiar and less flexible technologies like ATM or Sonet/SDH," said Chen. "All that is set to change with the advent of carrier-class Ethernet services and transport." "In the next 10 years, Ethernet will inexorably take over the metro," stated Michael Howard, principal analyst and co-founder of Infonetics Research. "Of course, there will never be a wholesale change because of the Sonet/SDH installed base, but every year Ethernet will account for a larger portion of metro capital expenditure." Howard predicts a $5.7bn, or about £3.5bn, market for metro Ethernet hardware in 2006. Despite depressed telco spending everywhere else, this optimistic picture of expenditure is echoed elsewhere -- and the services market could be even larger. "Even where overall spend is flat or reducing, the metro area is where [telcos'] budget is focused," said Ian Keene, VP and chief analyst for the Gartner Group. Telcos working towards an Internet Protocol (IP)-based infrastructure for services will have to spend what money they have on the metro, he said. Gartner predicts a $14bn market for metro Ethernet services in 2006. The MEF specifications couch network parameters in terms which telcos will understand, including "Ethernet virtual circuits", which mimic the virtual circuits on ATM networks, and "committed information rates" and "peak information rates" like those provided by existing telco services. The standards will be referenced by the telco standards body, the ITU (International Telecommunications Union) -- in itself a very big indication of Ethernet's arrival in the telecoms area. "This is very important," said Howard. "The focus of Ethernet has been at a technical level. But operators need to hear what kind of services can be offered." A major effort has been put into making metro Ethernet resilient, with the MEF specifications providing an alternative to Ethernet's "spanning tree algorithm", which will allow the networks to recover from a broken link within 50 milliseconds, matching the performance of Sonet. As the products emerge, users should see that end-to-end Ethernet services between locations will be cheaper and more flexible than before. For more detail, read this extended feature.