Corvis Goes Electric
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ATLANTA -- Supercomm 2001 -- Corvis Corp. (Nasdaq: CORV - message board) set a crow among the corn earlier this week when it announced a new optical switch at Supercomm 2001 (see Corvis Unveils 'Multiband' Switch ).
At first glance, the CorWave Optical Convergence Switch (OCS), as it's called, looks like a direct competitor to the CoreDirector from Ciena Corp. (Nasdaq: CIEN - message board).
As it so happened, Ciena announced a big upgrade of its switch at the same time (see Ciena Upgrades Products ). To complicate matters further, Sycamore Networks Inc. (Nasdaq: SCMR - message board) also announced developments aimed at catching up with Ciena in the market for grooming switches (see Sycamore Intros Grooming Switch ).
So, what's going on?
Corvis's new switch comes from its acquisition of Baylight Networks last year. In its initial form, it aims to do exactly what Ciena's CoreDirector does -- switch STS1s (51.8 Mbit/s channels) and bundle them together so that service providers can provision pipes in 155-Mbit/s increments.
The first version of the switch, scheduled for shipment by early next year, will occupy a single shelf and have a capacity of 240 Gbit/s, sufficient for 96 OC48 (2.5 Gbit/s) ports. "It's double the density of the CoreDirector," says Geoffrey Dive, a vice president of Corvis's Baylight Networks division.
Later on -- in the middle of next year -- Corvis plans to offer ways of linking together as many as 48 of these switches. This will amount to more than 4,000 OC48 ports, although Dive isn't expecting anybody to want that sort of capacity any time soon.
That, however, is just for starters. Corvis is planning to add a second type of switch to the OCS. These two types of switches will coexist in the same chassis like a double-yolk egg and will be linked together so that the combined entity can route whole wavelengths on and off Corvis's all-optical backbone as well as pack and unpack the wavelengths with lower bandwidth connections.
The fabric for the STS1 switch is electrical, a home-grown ASIC (application-specific integrated circuit), while the new fabric will be optical. It will be based on arrays of tiny tilting mirrors in MEMS (micro-electro-mechanical system) subsystems, according to Dive. The MEMS stuff is scheduled to ship in mid 2002.
So, why does Corvis need to put optical switching fabric into this switch, if it's already got an all-optical core switch? The answer is that they're totally different animals, according to Dive.
Corvis's core switch is genuinely all-optical. It's integrated with Corvis's transport systems and is able to route light from one fiber to another without converting it back into an electrical format at any point.
In contrast, the optical element of Corvis's new switch is more like the LambdaRouter from Lucent Technologies Inc. (NYSE: LU - message board), according to Dive. It has an optical switching fabric, but the light coming in and out of the MEMS subsystem has to be boosted in power by regenerating the signal electrically. MEMS switches have too high losses to do otherwise, Dive contends.
Having an electrical interface fits in just fine for an edge switch like the OCS, according to Dive. It's needed to link in with the STS1 grooming element, and it's also in a location where carriers need an electrical interface for network management purposes.
Baylight Networks was founded by a bunch of engineers with a long track record of designing the silcon for crossconnects at Alcatel SA (NYSE: ALA - message board; Paris: CGEP:PA). The company started out developing the architectural concept of the OCS and designing ASICs for it, knowing that it would need to link up with a systems vendor sooner or later, according to Dive, who was the CEO.
"A mutual friend" -- Vinod Khosla of Kleiner Perkins Caufield & Byers -- put Dive in touch with Corvis. After talking to David Huber, Corvis's CEO, Dive says he was amazed how well the two companies' ideas dovetailed. "I said this is a match made in heaven."
The proof of the pudding, of course, will be in the eating.
- Peter Heywood, Founding Editor, Light Reading
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