It's not Caspian. That's one of the main things Lawrence Roberts wants everyone to know about his new company, Anagran Inc.

But there's plenty more that Roberts, founder of now-defunct IP equipment vendor Caspian Networks, is keen to say about Anagran, which today unveils its maiden product, the FR-1000 Intelligent Flow Router.

The FR-1000, says Roberts, is an edge router that can control traffic more efficiently than deep packet inspection (DPI) products, allowing TCP networks to run at 95 percent of capacity instead of the usual 30 percent. It's a 1U box with 48 Gbit/s of capacity (not double-counting inputs and outputs), and has its roots in the Flow-Based Networking that was also the basis of Caspian Networks's router.

But Roberts left Caspian more than three years ago, convinced the company wouldn't fly. And he was right; Caspian folded last year. (See Caspian Closes Its Doors.)

Roberts is known for a lot more than Caspian. He's part of that elite group that helped build the Internet in the first place. (See Dr. Lawrence Roberts.) And, with Robertsian flair, he's willing to proclaim that Anagran could "shift the Internet to a fundamentally new technology."

But he's worried that people will dismiss Anagran as a Caspian clone.

"Caspian came at a time when it looked like it should be a core box," Roberts says. "Their margin was too low, even though the product worked and everybody was happy with it. I had quit halfway through because I saw the margins would be zip, and I thought there were a lot of other things we could do with the technology."

Compared with Caspian's costs, Anagran comes cheap. The company first came to light in 2004 as Roberts collected his early funding. Three years later, investors have put just $28 million into the 75-employee company. Caspian's third round alone was worth three times that. (See Supercomm Snippets: The Sequel, Anagran Raises $8M, and Anagran Attracts $12M.)

Roberts was able to keep development costs low by relying on off-the-shelf chips, something startups couldn't necessarily do circa 1999. The heart of the FR-1000 is an FPGA programmed with Anagran's algorithms, alongside what Roberts describes as an inexpensive routing chip. All told, the box lists for $70,000.

Anagran isn't just an exercise in pinching pennies, though. Roberts says he's spent the last few years expanding on what he started with Caspian, coming up with a more powerful way to use flow-based networking.

So, what is the FR-1000?

Inside the box
Anagran's router was conceived as an add-on to live networks, something that would be deployed as an aggregation box at the network edge.

Like Caspian, Anagran uses flow-based routing, where the router processes traffic in terms of flows and not just by individual packets. But this time, Anagran adds the wrinkle of being able to control the bandwidth used by each flow.

The goal is to avoid the high packet loss that comes when the network gets overloaded. Put differently, Anagran claims to turn TCP into a better juggler, letting the network maintain high throughput on a higher number of flows.

When a normal router reaches overcapacity, it starts discarding packets, often in a round-robin fashion, sometimes affecting traffic flows that aren't contributing to the problem. "The result is, everybody slows down at once. Then, they all start speeding up at once," Roberts says. To avoid this oscillatory behavior and the congestion that comes with it, carriers run their routers at around 30 percent of capacity, to leave enough headroom for surges in traffic, according to Roberts.

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