Optical/IP Networks

Siemens Cooks Up Multiservice Platform

Seabridge Ltd., which is part of Siemens AG (NYSE: SI; Frankfurt: SIE), is cooking up a next-generation multiservice switch that can handle both cells and packets natively. The new platform will probably be announced officially in September, the company says, and should be available in mid 2003.

The development came to light earlier this week when Azanda Network Devices announced Seabridge's intention to use Azanda's traffic manager chip inside the new platform (see Seabridge Picks Azanda).

Called XpressPass 340, the new platform will be the successor to Seabridge's existing XpressPass product family of multiservice switches. Designed to carry both ATM and IP traffic, XpressPass adapts data, voice and video from digital subscriber line access multiplexers (DSLAMs), 2G/3G mobile base stations, and wireless local loop connection points to ATM. The product family is well-established in Europe, being installed at major European carriers such as Deutsche Telekom AG (NYSE: DT).

The key difference with XpressPass 340 lies in how it switches traffic, according to Eyal Assa, head of the R&D group working on the new platform. Most multiservice switches are really ATM switches, and must convert Ethernet traffic into ATM cells for switching. At the opposite extreme, edge routers treat everything as IP, converting ATM cells into packets for switching.

XpressPass 340 will do both, says Assa. Traffic flows through the switch in its native format, only being converted if necessary to connect an ATM network to an IP network, or vice versa.

"When you do a conversion, typically you have to pay a 'cell tax'," he says. "In our switch fabric that's not the case." By cell tax, he is referring to the fact that packets and cells can be different sizes, so when one is converted the other, there is usually some wasted space.

Seabridge says it picked Azanda because its traffic manager chip is one of the few that can handle both ATM and packet traffic. It contains an integrated cell segmentation and reassembly (SAR) engine.

Azanda was chosen over rival Vitesse Semiconductor Corp. (Nasdaq: VTSS) because, among other things, Azanda's chip supports full-duplex traffic, while Vitesse's chip can only handle half-duplex traffic, according to Greg Wolfson, Azanda's VP of marketing.

It turns out that Seabridge's special something -- the ability to keep native formats in the switch -- isn't so special after all. Fore Systems, which was acquired by Marconi PLC (Nasdaq/London: MONI), probably thought of it first, although its product targets different applications. Fore Systems' BXR4800 switch scales up to 480 Gbit/s, making it appropriate for the core, or "edge of the core" applications (see Marconi Unveils Big Switch/Router). Seabridge's new platform, on the other hand, is 40-Gbit/s switch, placing it much nearer the edge.

Other vendors, such as Coriolis Networks Inc. and Native Networks Ltd., are also potential competitors, since they are also developing multiservice switches that can handle cells and packets in their native format (see Coriolis Scores $32 Million).

Seabridge's competitive positioning won't become clear until it announces the product. In fact, the reason it hasn't announced it yet is because it hasn't decided how to position it, says Inna Novikova, its director of business development.

What this really means, apparently, is that Seabridge hasn't yet signed up a customer for the new product.

"You don't tend to get these multiservice boxes released with the full range of interfaces from day one," contends Geoff Bennett, distinguished engineer, technology strategy with Marconi. It takes a lot of engineers to get these boxes through development, he adds, and most companies have a very limited number of engineers working on new products. "Seabridge needs a customer to tell them which interface to develop first."

— Pauline Rigby, Senior Editor, Light Reading

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