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Taming the Broadband Beast

Unlike Al Gore, Larry Roberts is a guy who can toss off a phrase like “when I started the Internet” and get away with it.

In the late 1960s, Roberts, 69, led the team at the U.S. Department of Defense’s research agency that developed Arpanet, the packet-based network that was a predecessor to the Internet. His latest gig is founder and CEO of Anagran, a startup that promises to give cable operators way more bang for their data-networking buck.

The problem with today’s Internet, Roberts said, is that it was built to account for peaks in demand. That means there’s a lot of unused capacity: U.S. Internet providers run their networks at an average of 25% utilization, he said. “It’s engineered to not lose traffic.”

That’s not only wasteful. It’s also unsustainable, Roberts argues. “In the past we had a narrow edge and large core,” he said. “Now we have a broadband edge, and the core can’t keep up. So service providers have to change.”

With his company’s debut product, which Anagran calls a “flow router,” Roberts aims to make the Internet more efficient.

Here’s how it works: The Anagran router manages Internet Protocol networks by looking at flows, which are end-to-end activities like a video stream or a voice call. It examines the network traffic, then carves out the necessary bandwidth for the duration of the flow. By contrast, a traditional router must examine the individual bits in a network transmission and make a separate decision about where to send each one of them.

A conventional IP router operates the way the U.S. Postal Service generally sorts mail: Every envelope must be analyzed to figure out where it’s going and what priority to give it (like whether it’s first-class mail). A flow router can understand that a few million important letters are about to go to the same address — and it makes the decision about how to send them there only once.

“The Anagran system essentially applies circuit-switching to a packet-switched world,” said Michael Kennedy, a managing partner with Concord, Mass.-based consulting firm Network Strategy Partners.


The approach means, theoretically, an Anagran router is much less likely to get overloaded at high utilization rates.

Instead of dropping bits willy nilly like a packet-based router does when too much traffic blasts in the front door, Anagran’s flow router proactively watches incoming flows and throttles back the bandwidth available to less time-sensitive applications (like peer-to-peer file-sharing programs), while preserving the space needed for voice and video.

“The reason you can manage flows much better [than packets] is because they have a predictable rate,” Roberts said. “That means I have much more control than if I’m trying to handle this swarm of bees.”

The Anagran router can operate at 95% capacity, according to Roberts, and never max out.

In practical terms, that means “if you’re a cable operator offering a triple play, we can ensure video and voice don’t get stepped on by the data,” Anagran vice president of marketing Dan O’Farrell said.

And, by routing based on flows instead of packets, Anagran can direct IP-based voice or video using a fraction of the horsepower required by conventional routers to do the same kinds of tasks. “We’ve eliminated some very power-hungry functions,” Roberts said.


Anagran’s FR-1000 router is just 1.75 inches high and consumes 300 watts. A device from Cisco Systems that provides comparable processing capabilities would be 10 times as big and eat up 2,000 watts, according to Roberts.

To be sure, a whole category of existing networking products provides the same functions as Anagran’s router. Deep-packet inspection systems crack open IP packets and make the same kinds of calculations to allow voice traffic, for example, to have priority over Web-based applications (a feature called quality of service).

The difference is that using a traditional routing architecture “is a very expensive way to do quality of service,” Roberts said.

Anagran’s FR-1000 Flow Router, to be commercially available starting this month, will cost $70,000 for a system with 48 Gigabit Ethernet ports. That’s at least one-third the cost of a deep-packet inspection switch with similar capacity, the startup claims.

The big change in the computing industry that has made a flow router possible is the drop in the price of memory. “It hasn’t been economical to have the memory for the flows before,” Roberts said.

Network Strategy Partners’ Kennedy said cable operators may be more interested than telcos in Anagran’s technology, because cable backbones are typically based on Ethernet already.

But even if it does have a better mousetrap, Anagran faces the same challenge all networking startups encounter — that major service providers don’t want to take a risk on a small, unproven technology company, Kennedy said. And by the time network operators are ready to deploy such flow routers, big vendors like Cisco, Juniper Networks and Alcatel-Lucent may be offering similar products.

“The largest service providers were burned very badly in the early 2000s by working with startups,” Kennedy said. “They’re just not going to do that again.”