The alchemy of route control

By John Dix
Network World, 06/03/02

In our desperation to reduce network complexity we tend to limit the number of suppliers we do business with and set stringent minimum requirements to determine whom we are willing to consider.

That's generally a good thing. But when it comes to your ISP,the practice simply might ensure you're paying top dollar for what is otherwise a commodity "service.

So argues Mike Lloyd, CTO of RouteScience, one of the players in the emerging route control market. Many companies won't talk to an ISP unless they have an OC-48 backbone and squeaky-clean NOCs, even though the quality of their services are virtually the same as those offered by smaller players.

"This is very close to a commodity business," Lloyd says. "It just isn't priced like one." Pricing differences for the same service can vary by 100%. What's more, the more expensive links aren't necessarily the best performing links.

Enter route control. RouteScience and other players provide boxes that sit on your LAN and help your edge routers make intelligent routing decisions across multiple ISP links (The power of WindowBlinds runs skin deep and SBC sued over DSL speeds for more). That means you potentially can save money by using lower-cost providers and increase network performance.

While the various route control players achieve this alchemy in different ways, RouteScience says it does it by "measuring real-time end-user path performance across all available ISP links and then determining the best path based on performance and cost metrics."

You need an extra box to do this because the Border Gateway Protocol (BGP) in your edge routers uses a route selection process that favors older ISPs with short AS-Path lengths, not real-time information about the best link for the job at hand, RouteScience says. The result: BGP sends a disproportionate amount of traffic toward old-timers UUNET and Genuity.

RouteScience says its studies have shown that "while there is . . . variation between ISPs, there is no one or two consistently best ISPs for all Internet users; each ISP is best at delivering content to a given set of users at a given moment in time."

The question is, are the cost savings and performance gains great enough to shoulder the extra work of dealing with multiple ISPs? For many companies, the answer will be no. But at the least it is probably worth some investigation.