Startup Velio Communications Inc. is planning to announce a chip on Monday (March 19) that could help vendors build bigger optical “grooming” switches -- ones that bind together multiple STS1 (51.8 Mbit/s) connections across optical networks.

The chip, called the VC2002, incorporates a 72x72 port grooming switch and 72 pairs of OC48 (2.5 Gbit/s) input/output devices, all on the same piece of silicon. The chips can be used singly in add-drop muxes and similar gear, or they can be used in large numbers to create whopping big grooming switches.

A hundred-twenty of Velio's chips are needed to make a box with as many as 1,728 OC48 inputs and 1,728 OC48 outputs using a 3-stage Clos architecture, according to Velio. A 5-stage Clos switch capable of handling as many as 41,272 OC48s, is theoretically possible, the company claims.

This is a big deal for vendors struggling to make larger grooming switches. Right now, 512x512 is the maximum for 3-stage Clos architecture switches. Anything beyond that pushes the limits of current semiconductor technology (see Brightlink Works on Its Grooming).

Velio appears to be leading the field with its new chip. The closest competitor is probably Vitesse Semiconductor Corp. (Nasdaq: VTSS). It has a 64x64 port grooming chip, called the VSC9182, which incorporates input/output devices and is a quarter of the size of Velio’s VC2002, according to Andrew Schmitt, Vitesse’s director of product marketing. But -- and it’s a big but -- Vitesse’s chip has a port speed of 622 Mbit/s, not 2.5 Gbit/s

Schmitt hints that Vitesse might have a product equivalent to Velio's by the time Velio goes into commercial production of its VC2002, which is scheduled for the second half of this year.

Bill Woodruff, Velio’s VP of marketing, says the startup is already shipping samples to a lead customer. It’s one of the leading OEO switch players, he adds, which probably narrows it down to Ciena Corp. (Nasdaq: CIEN), Cisco Systems Inc. (Nasdaq: CSCO), or Sycamore Networks Inc. (Nasdaq: SCMR)

Woodruff also draws attention to the recent announcement of a giant 16,384x16,384 grooming switch, by Altamar, a spinoff of Ditech Communications Corp. (Nasdaq: DITC; Frankfurt: BDTH). He notes that it's based on 5-stage Clos architecture (see Altamar Unveils High-Density Switch). The implication is that it might be based on Velio's chips.

The OC48 port speed of Velio’s switch chip is a big deal, according to Woodruff. The technology behind this -- which cleans up signals so they can go farther over backplanes while cutting power requirements -- has already helped Velio launch a family of breakthrough serializer/deserializer (SerDes) chips targeting 10-gig Ethernet switches (see Velio Cleans Up).

The VC2002 incorporates 72 pairs of these SerDes devices in addition to the switching fabric itself. Previously, the SerDes devices would have been on separate chips, according to Woodruff. Integrating everything means that a 256x256 grooming switch can be crammed into a single shelf. It also reduces power requirements even further, to just 0.3 watts a port, according to Velio.

Vitesse’s Schmitt says there’s more to developing these types of chips than reducing the size and power consumption of equipment. It’s even more important to provide ways for chips to be reconfigured for different Sonet environments via a simple software change. It’s also important to ensure that such chips can support Sonet’s various protection schemes for rerouting traffic around problems -- which he cites as a strength of Vitesse’s chips.

Velio’s ability to match Vitesse on this score will become clear later this year, when the VC2002 starts shipping. The chip costs a cool $2,580 when bought in quantities of 5,000.

-- Peter Heywood, international editor, Light Reading http://www.lightreading.com