This appears to say Guilder's a long ways out there
lightreading.com
sorry if this was already posted
True optical routing, in which routers can read the addresses and other information carried in photons, is a long, long way away. "To switch packets in light would require a transducer that can convert light signals. Those are barely in the lab," says David Tolwinski, president and CEO of Tenor Networks Inc. (http://www.tenornetworks.com), an optical networking start-up.
"True photonic routing is so far in the future that I don't have a clue when it will happen," says Fred Harris, director, network planning and design for Sprint Corp. (http://www.sprint.com/). "The only thing you will get is wild guesses."
And even trying to implement real routing may be misguided, according to some vendors. "Electronics is good at switching. Optics is good at transmission. Let each one do what they're good at," says Victor Mizrahi, chief scientist at Ciena Corp. (http://www.ciena.com), which recently acquired Lightera, a startup with an optical cross connect that has an electrical core.
Even if vendors could deliver scalable all-optical networks, practical issues may discourage carriers from rolling them out in real life.
Right now, for instance, there are no standards for carrying management information in optical networks, so carriers may be forced to retain electrical interfaces so they can pinpoint faults.
There's also no way of supporting error-correcting protocols on optical networks. Which might force carriers to use more expensive transmission equipment to minimize noise in the first place.
Carriers might also discover that they need electrical interfaces to regenerate the right color light. "There's no standard for connecting one shade of blue light to another shade of blue light," notes Tellium's De Vito. Tellium has a cross connect with an optical core, but has to bolt on electrical equipment to convert light to the colors used in whatever DWDM system is in use by its customers.
The only way of avoiding this issue at present is to buy a complete package of switching and transmission equipment from the same vendor - the solution being proposed by Corvis and Nortel's Qtera.
It's worth noting that Tellium is one of the few vendors shipping commercial all-optical cross-connects right now. Corvis plans to ship this quarter, Qtera in the second half of this year and Lucent by the end of 2000. That's when the bragging about all optical networks will have to stop and carriers will be able to debunk the claims about all-optical networks for real. |
