Under control

Route control products and services are primarily designed to pick the best paths for Internet traffic at companies that use more than one ISP. But early adopters of the technology say it delivers a range of additional benefits.

Route control products and services are primarily designed to pick the best paths for Internet traffic at companies that use more than one ISP. But early adopters of the technology say it delivers a range of additional benefits.

In deciding which way traffic should go, route controllers gather data that companies can also use to decide how much more bandwidth they might need to buy, to ensure that ISPs are living up to service-level agreements (SLA) and to negotiate new service provider contracts.

Route controllers are network appliances that sit behind firewalls in multihomed networks as peers to Border Gateway Protocol (BGP) routers. They probe to determine how well each available ISP connection is performing and pick the best one. Vendors of this type of equipment and service include netVmg, Proficient, Route Science Technologies and Sockeye.

Jonathan Davies, COO of hosting provider UPNetworks in San Francisco, says his Proficient equipment directs as much traffic as possible to his Williams Internet link rather than his others because it is one-third the cost. “We clearly want to use the cheap stuff whenever we can,” he says, as long as performance is up to par.

BGP alone picks the route that involves the fewest router hops. But users want to factor in other parameters such as delay and which link costs the least. Route controllers do this and then update BGP route tables accordingly to determine which ISP traffic gets sent to. Later, if another ISP’s performance becomes the best choice, the route controller changes the route tables again.

Widener University in Chester, Pa., uses RouteScience equipment primarily to keep performance up by preventing any one ISP link from becoming overloaded. When a certain percentage of one link is being used, the box shifts more traffic over to links that haven’t reached their high-water mark, says Larry Pfeifer, Widener’s network engineer. This is a core function of route control equipment, but it has value in helping users figure out how much more capacity to buy when traffic increases.

Before, if BGP was favoring one link, and it became congested over time, the school had to buy more bandwidth for that link. But it was never clear how much more bandwidth was really needed because BGP could be unpredictable, Pfeifer says. With route control, Widener now knows its traffic will be distributed across its links, so it can buy extra capacity from any of its ISPs based on how much traffic servers are generating. “Now we apportion bandwidth going out more fairly and use the full capacity we buy. It’s huge,” Pfeifer says.

Data gathered by route control gear in the course of performing its functions can be used to keep ISPs honest, says Scott Ellentuch, president of TTSG Internet Services in New York. The data TTSG gathers from Sockeye’s route optimization service tells whether its ISPs are meeting SLAs.

TTSG also shares the data it gathers with its ISPs in hopes of encouraging them to improve their service, Ellentuch says. If the ISP sees that TTSG is diverting traffic from its link because performance is subpar, it might take steps to improve, he says. Or if it sees that traffic is being diverted because another ISP is less expensive, it might offer a better deal.

While route control gear can help customers avoid ISPs whose networks are congested, at the moment, sharing route control data about these problems with ISPs can help prevent brownouts. Sockeye gathers the information ISPs need to track down the roots of problems. “Providers demand a trace route, and this gives us the documentation we need,” Ellentuch says.

VenturesOnline, a hosting provider in Greenwich, Colo.,  uses netVmg gear to pick ISP connections and hopes the equipment also can help the company pit its ISPs against each other as they bid to provide additional capacity, says Fred Franzel, VentureOne’s vice president..

With many users trying to connect to many customers’ servers in VenturesOnline’s data center, it was difficult to shift large amounts of traffic to underused links by manually adjusting BGP tables, Franzel says. The netVmg gear allows identifying and shifting large chunks of traffic automatically via preset policies so VenturesOnline can maximize use of its available connections. If the company needs more bandwidth, it can seek competitive bids from its three ISPs rather than being forced into buying more bandwidth from the provider that BGP favors. “We hope to get better-negotiated contracts for minimum [traffic] commitments,” Franzel says.

The policies that automate route selection also save a lot of time, he says. “I was hand-writing policies on Juniper routers to adjust the BGP tables. I could make a change and 5 minutes later have to change it again,” Franzel says. His company has Internet connections from Time Warner Telecom, AT&T and Yipes Enterprise Services, and changing route tables to balance traffic load was literally a full-time job. Now Franzel doesn’t have to do any of the BGP updates, and the traffic is distributed more effectively than when he did them himself.

Northwest Multiple Listings in Kirkland Ore., gains benefits from using F5 Networks’ Web acceleration equipment that are similar to those gained by route control product and service users, says Raymond Williams, Northwest’s network developer. Real estate agents who tap Northwest’s database of properties for sale can access servers via connections with three ISPs, and F5’s equipment keeps any one link from clogging up at peak times.

The F5 gear has enabled Northwest to dump BGP altogether and even give up its autonomous system designation, which is needed to participate as a BGP peer. Using the equipment also relieves the stress of making BGP changes that could affect performance of routers outside Northwest’s network, Williams says. Dropping BGP also increased CPU availability on routers 10% to 15% and freed router memory that was maintaining BGP tables, he says.

While the unexpected benefits of route optimizing gear have been many for early adopters, it is important to keep in mind that the offerings, which can range in price from $15,000 to $250,000, also can result in big cost savings. For instance, TTSG is saving money with route control technology because it keeps the company from overrunning its minimum commitments. TTSG has dropped from paying $16,000 to $17,000 per month in bandwidth overruns to about $1,000 per month, Ellentuch says.

“[Route control gear] gives us more leverage with our providers because we can go back to them with specific performance information,” he says.