Are you smart or intelligent?

Are you smart or intelligent?

Stephen M. Hardy

Editor in Chief

stephenh@pennwell.com

Several new optical networking companies have made their debuts in the last eight months. While each has attempted to project a unique vision within its network niche--from the core to the metropolitan area to the local loop to the spaces in between--a common thread among many of these offerings is the attempt to bring "intelligence" to fiber-optic networks.

Of course, part of introducing something new is contrasting it with what has come before. For example, each of the startups highlights the differences between their equipment and the Synchronous Optical Network/Synchronous Digital Hierarchy (sonet/sdh) network elements they hope to replace. But another cornerstone of market positioning for these new offerings tends to remain in the background, unless you press the company spokespeople. That is the difference between these new "intelligent" approaches and another philosophy that isn`t nearly as old as sonet/sdh, but which these offerings also threaten to push to the margins of the network: optical internetworking.

When they introduced optical internetworking, Cisco Systems and Ciena offered the first viable challenge to the sonet/sdh equipment hierarchy. Traffic at the network core has reached unprecedented levels while becoming increasingly data-centric, they reasoned. Therefore, it no longer made sense to meet growing data demands with a voice-optimized architecture--why not remove the sonet/sdh layer from the network core and replace it with data switches? The incorporation of sonet/sdh-based high-speed optical interfaces would allow these switches to communicate with each other directly at the optical layer, with dense wavelength-division multiplexing (DWDM) equipment serving as onramps to the optical highway.

All in all, optical internetworking looked like a smart way to configure networks--particularly the brand new networks of the emerging alternative carriers--for the Internet-driven traffic demands of tomorrow.

But the new generation of optical internetworking startups has a somewhat different view. As quoted in the article "Startups tackle optical network evolution from divergent angles," page 34, Charles Chi, vice president of marketing at Lightera Networks, says, "Carrier customers say that the optical core could be dumb, point-to-point bandwidth, or it could be intelligent, dynamic bandwidth that could be managed better." Optical internetworking--at least given the current capabilities of the gigabit data switches--represents the former option, in Chi`s opinion. However, said Chi, "What carriers tell us is that they`re looking to build a much more manageable, dynamic, intelligent core." To Chi, this means intelligent optical transmission equipment in between the routers and the optical core, not just DWDM equipment.

One wonders how such sentiments sit with an emerging carrier such as Enron Communications, which has embraced the optical internetworking philosophy in at least the initial roll out of its all-Internet protocol (IP) network. Enron plans to follow the classical optical internetworking paradigm, right down to linking Cisco routers with Ciena DWDM equipment. A high-level source at Enron recently told me that he has complete confidence in Layer 3-based traffic management. Of course, Enron has announced plans to transmit only one kind of protocol--IP--over its network, which significantly simplifies the network equation.

Perhaps the current purity of Enron`s traffic mix indicates how the debate between "intelligent" optical networking and optical internetworking will be resolved within the carrier community. The degree of intelligence necessary in future optical networks likely will depend on the complexity of the traffic pattern--particularly in terms of how many protocols must be supported simultaneously. It appears this will be Ciena`s message; now that it has purchased Lightera and Omnia, it has a foothold in both the intelligent and optical internetworking camps.

At the press conference announcing the new acquisitions, Ciena spokespeople said that there was no conflict between the intelligent vision described by Lightera and the optical internetworking philosophy Ciena helped popularize with Cisco. But it seems inevitable that conflicts will indeed arise in the marketplace--where carriers will have to decide if they need to be completely intelligent, or just smart.

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