CHICAGO – Supercomm – Cisco Systems Inc. (Nasdaq: CSCO) officially has a reconfigurable optical add/drop multiplexer (ROADM), as the company announced the feature offering for its ONS 15454 at Supercomm this week.

Light Reading had caught word of Cisco's ROADM plans in February at the Optical Fiber Communication Conference (see Vendors Race for Reconfigurability). But the ROADM arrival comes with a twist: Meriton Networks Inc. also added ROADM to its product this week, and the startup claims the technology has helped it beat the 15454 in 10-Gbit/s metro rollouts (see Meriton Goes Long Haul).

Both announcements tie into a predicted swarm of interest for ROADMs at Supercomm (see Supercomm: A ROADM Show?). The ROADM offers the promise of being able to switch at the wavelength level, changing the add and drop assignments at will through remote software, rather than sending engineers to the site.

Carriers are warming to the concept because of the potential savings in operating expenses. "The biggest thing that's driving [ROADMs] is the unpredictable nature of the traffic," says Jim Sauer, Cisco director of product management.

A number of RBOCs -- among them BellSouth Corp. (NYSE: BLS), SBC Communications Inc. (NYSE: SBC), and Verizon Communications Inc. (NYSE: VZ) -- have issued RFPs for ROADM-based upgrades of their optical infrastructures. Opinions differ on whether the RBOCs are just testing the waters or are serious about widespread use of ROADM technology.

Other metro Wavelength Division Multiplexing (WDM) vendors with ROADM technology include Marconi Corp. plc (Nasdaq: MRCIY; London: MONI), Movaz Networks Inc., Tropic Networks Inc., Fujitsu Network Communications Inc. (FNC), and the late Photuris, whose technology was acquired by Mahi Networks Inc. (see Mahi Nabs $70M, Photuris Assets). Lucent Technologies Inc. (NYSE: LU) and Motorola Inc. (NYSE: MOT) are reselling Movaz's equipment; and Nortel Networks Ltd. (NYSE/Toronto: NT) reportedly has ROADM in the works as well (see Photuris & SBC: The Inside Story).

Supercomm is indeed proving to be "the coming-out party of ROADMs as a standard feature of metro WDM systems," as Michael Howard, principal analyst for Infonetics Research Inc., puts it. What's key is not just the add/drop ability, but the fact that many of these ROADMs automatically adjust optical power levels after each change, removing one of the trickier elements of the manual add/drop process. "The carriers will be able to think of WDM as a new tool, something where you can light up a new wavelength in minutes rather than weeks," Howard says.

Cisco's ROADM controls 32 wavelengths, allowing adding or dropping in any permutation. It comes in two parts: a double-width card for the wavelength-selective switch -- the element that blocks wavelengths -- and a single-card demultiplexer. Meriton's ROADM is smaller: a single, half-height card that can demultiplex 40 wavelengths.

Neither ROADM is home-grown. Cisco isn't identifying any component partner(s), but Meriton gladly offers that its card is based on a wavelength-selective switch designed by startup Capella Photonics Inc. (see Capella Cashes In).

In Meriton's case, the ROADM has less to do with wavelength services than with the move to 10-Gbit/s transport. The company developed a ROADM card for its 7200 OADX as a way to cut down on expensive 10-Gbit/s optics.

The 7200 uses an electronic switching fabric, which requires optical signals to be converted to electrical form and retransmitted as optical, an architecture that, of course, uses optical components for that last step. "There are going to be many cases when we want to do pass-through of 10-Gbit/s [wavelengths] just to avoid the optics cost," says Rob Gaudet, director of product management.

That leads to Meriton's new competitive pitch. Rather than upgrade a set of Cisco 15454s with 10-Gbit/s cards, Meriton suggests carriers leave them in place for traffic at 2.5-Gbit/s and below. A set of new 7200s could then form a kind of 10-Gbit/s overlay, which would carry high-speed traffic that could be switched wavelength by wavelength.

It might sound like extra work and expense, but Meriton officials claim the idea has won them work from some Cisco customers. "They came to the conclusion that upgrading the 15454s to OC192 was not cost-effective," Gaudet says.

— Craig Matsumoto, Senior Editor, Light Reading

Archives of Related Light Reading Webinars: