February 15, 2012
New Research, Interoperability Demo Show OTN Switching Poised for Growth
By Joan Engebretson
A couple of news items this week underscore some important new developments in optical transport networking (OTN). The OIF (News - Alert) revealed that it is coordinating an ongoing global interoperability test of Ethernet services over OTN transport. And apparently that sort of testing is just in time, as Infonetics (News - Alert) is forecasting strong OTN growth, driven largely by growth in OTN switching revenue.
Service providers are highly interested in OTN switching because it promises to enhance network efficiency by enabling multiple services to share a wavelength.
According to Infonetics, sales of OTN switching equipment currently comprise only about eight percent of the OTN market, with more mature OTN transport equipment representing the remaining 92 percent. But that’s expected to change substantially over the next few years, as service providers get serious about deploying OTN switching.
“OTN is really an umbrella for two different layers—electrical and photonic,” said OIF President Jim Jones on a phone call this week. “Up to now, service providers have extensively deployed photonic [OTN implementations]. Now electrical is coming on.”
OTN transport is a mature technology that underlies DWDM equipment, adding forward error correction and some other overhead to enable service providers to put 10 Gig E or other connections onto a wavelength, explained Jones, who is also optics marketing manager for Alcatel-Lucent (News - Alert).
In contrast, OTN switching “enables you to map multiple services [onto a wavelength] using the electrical switching layer,” said Jones. As he explained, services are actually combined before they are put on a transport wavelength.
Until recently such OTN capabilities were “more closely aligned” with data rates of Sonet and SDH, but new standards developments have made OTN more packet-friendly.
“OTN and Ethernet together was a natural combination,” said Jones. And that combination is an important focus of the interoperability testing.
“Complex specifications always have some degree of ambiguity,” said Jones, adding that an important goal of the demo will be to provide input to standards bodies with the goal of eliminating some of this ambiguity.
The interoperability test, which interconnects equipment located in carrier labs around the globe, has been underway for about two months, Jones said. Service providers participating in the test are Deutsche Telekom (News - Alert), France Telecom/ Orange, KDDI and Verizon. Manufacturer participants include Adva Optical Networking, Alcatel-Lucent, Ciena, Exfo, Huawei, Marben Products, Metaswitch and Tellabs (News - Alert).
OTN switching revenue jumped 132 percent between 2009 and 2010, according to Infonetics, even without some of these interoperability issues being resolved, which suggests that a big boom is indeed likely moving forward.
Joan Engebretson has been writing about telecommunications technology and the telecommunications industry since 1992. To read more of her articles, please visit her columnist page.
Edited by Rich Steeves
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