Carrier Ethernet technology is figuring prominently in service providers' data network evolution plans, even before
standards are finalized, according to "Service Provider Plans for IP/MPLS," a new research survey of 29 major service providers by Infonetics Research. While the results don't mean that traditional SONET and SDH will disappear from global service provider networks any time soon, Ethernet's rise to prominence is surprising even industry insiders.
Conducted annually to assess the router and switch requirements of service providers in North America, Europe and Asia Pacific, this year's IP/MPLS survey results show that operators are anxious to be able to simplify the layers in their networks, according to Infonetics President Michael Howard.
From a service perspective, video, IPTV, metro Ethernet service and VoIP are driving Carrier Ethernet and IP/MPLS traffic growth over the next three-to-five years, the survey showed.
"The biggest surprise in this study was service providers' planned use of connection-oriented Ethernet using developing PBT, PBT-TE and T-MPLS protocols that aren't standardized yet. They're brand new," Howard said, adding that it is an extremely unusual move for the telecommunications industry historically. "It's pretty gutsy because there are no standards yet, so it's a very strong statement."
A full 44% of providers surveyed by Infonetics in late 2007 said they have plans to use Ethernet tunnels in their networks in 2008 in general, and 15% and 19% respectively said they would deploy PBT and T-MPLS as the protocol of choice this year.
"I took our results to mean that carriers are very interested in the whole move to connection-oriented Ethernet, and many of them haven't chosen whether to go Provider Backbone Transport (PBT), or T-MPLS or both, but the idea is strong in their minds," Howard said.
An earlier 2007 Infonetics survey on metro-area networks revealed that a full 89% of service provider respondents were already using Ethernet in addition to SONET/SDH in their access networks, Howard said. What's driving Carrier Ethernet deployment in the access and metro network cores is the desire to enable the Internet to have the same qualities and capabilities as SONET/SDH using packet technology so providers don't have to continue to buy SONET/SDH equipment but get the same resiliency and reliability they're used to.
"Their big hope is to take a layer out of the network," Howard said, adding the caveat that it will be 15-to-20 years before SONET/SDH is a technology of the past. "Since SONET is a double-ring technology, carriers like to have redundancy in case of a failure, but 50% of the bandwidth is always waiting there in case there's a failure, and circuits have to be nailed up, so it's a waste."
"If providers switch to a packet technology like Ethernet, they still need to have an alternate path for redundancy, but they can use all of the paths all of the time, so they won't have 50% of their bandwidth lying fallow," Howard said.
Implications for equipment vendors
Service providers are looking toward enabling a data services layer comprised of IP, MPLS and Ethernet that rides on a transport layer that Howard calls a "fused Ethernet/WDM layer." That would mean no SONET/SDH, at some point. "We're seeing the first optical boxes with Ethernet switching capabilities, like Ciena's new CN 4200 multiservice transport platform, whose G10 module that puts Ethernet's switching and aggregation capabilities on a line card rather than on a separate Ethernet router or switch sitting beside the optical gear. Other vendors have also developed packet optical gear, he added.
As Ethernet tunnels become more available in optical gear, service providers can keep Ethernet tunnels in the optical layer for long distances without having to pop up to routers, so less traffic would be traveling through routers, Howard said. Still, router sales are expected to grow faster than optical gear, according to Infonetics. While carriers have incentive to drive cost out of network operations, it's not easy to do. "Things have to happen correctly and carefully, and you can't replace network layers on a wholesale basis," Howard said. "There are about 475,000 SONET and SDH rings in the world, and basically none has been taken out of service at this time."