10/23/2006 -- For more than a decade now, SONET/SDH has been the go-to standard for metro access, and it isn't going anywhere anytime soon.

But its displacement is really only a question of time, said market watcher Infonetics Research, which projects that Ethernet will come to dominate the metro space over the next 10 to 20 years.

For example, Infonetics said, among 25 top-tier service providers in North America, Europe and Asia-Pacific, the percentage of access or collector rings/mesh that are Ethernet will jump from 32 percent in 2005 to 60 percent in 2007 and beyond. "The trend is clear: Ethernet is growing in the access space to the detriment and displacement of SONET/SDH, as service providers continue to look for ways to reduce operating expenditures and enable new revenue streams," said Infonetics principal analyst Michael Howard in a statement. "And now that the No. 1 technical issue that was plaguing service providers rolling out metro Ethernet networks last year –- QoS -- is being addressed by manufacturers, the Ethernet adoption curve is speeding up."

Manufacturers have added new QoS features based on OAM standards, Howard noted, which has helped improve end-to-end QoS with carrier-class Ethernet products. One upshot of this, Infonetics said, is that QoS -- which topped last year's list of metro Ethernet challenges -- dropped to No. 7 this year.

Elsewhere, Infonetics said, all respondent service providers currently offer Ethernet services, while most plan to offer Ethernet over a variety of technologies, including fiber, copper, WiFi and WiMAX. What's more, 48 percent of providers plan to deploy next-gen hybrid Ethernet-WDM-SONET/SDH equipment. Established providers are ahead of upstart competitors in replacing SONET/SDH with Ethernet services, Infonetics said: Europe is moving the fastest in this direction, Asia Pacific the slowest.

Today, most service providers offer Ethernet services via VPNs; as a result, Infonetics predicts, all VPN service types will grow in usage by 2007, led by layer-2 point-to-point MPLS VPNs (or pseudowire) and VPLS.

Packetized voice services are among the most popular metro Ethernet offerings, along with private line over Ethernet, and a mix of video, storage-related and security-related services. Finally, more than half of service provider respondents indicated that they planned to deploy an all-Ethernet (or Ethernet/MPLS) network that combines residential/triple play and business traffic services. -Stephen Swoyer