ESnet's OSCARS Allows Users to Reserve Bandwidth

July 31, 2009

Linda Vu  |  |  510-495-2402

Most network traffic is transmitted on a “best effort” basis, meaning that there's a pretty good chance the packets will arrive as intended. But for the Department of Energy (DOE) researchers around the world who are sharing massive scientific datasets, the “best” just isn't good enough. Now, researchers can reserve bandwidth on Energy Sciences Network's (ESnet) circuit-oriented Science Data Network, with the On-Demand Secure Circuit and Advance Reservation System (OSCARS).

“OSCARS allows us to see the network as a resource—users tell us how much bandwidth they need, where the information needs to go, when it needs to be there—sand we guarantee the bandwidth to make that delivery,” says Chin Guok, ESnet network engineer and lead of the OSCARS development.

Managed by the Lawrence Berkeley National Laboratory (Berkeley Lab), ESnet connects thousands of researchers at DOE Laboratories and universities across the country with their collaborators worldwide. ESnet comprises two networks—an IP network to carry day-to-day traffic, including e-mails, video conferencing, etc., and a circuit-oriented Science Data Network (SDN) to haul massive scientific datasets. OSCARS was developed with support from DOE's Office of Advanced Scientific Computing Research (ASCR).

“The only way to make sense of information from big science experiments like the Large Hadron Collider, which will produce roughly 40 terabytes of data per day, is to divide up the work amongst hundreds of thousands of collaborators around the world, because no single supercomputing facility is capable of processing and storing that much information,” says Dantong Yu, who leads Grid Computing Group at the Brookhaven National Laboratory's USATLAS/RHIC Computing Facility.

“When that many researchers are relying on each other, a tool like OSCARS that guarantees data delivery is invaluable,” he adds.

Making a Reservation

According to Guok, the OSCARS service is easy to use and open to anybody with an ESnet account. Science users and application programmers, even those without a network engineering background, can make a reservation on ESnet's SDN by simply setting their desired parameters into a web interface at

Once an hour, OSCARS automatically harvests information about the network's topology, determine if there are physical changes in the network, and then updates its database accordingly. When a new reservation is received, the system refers to the database to check for conflicts with existing requests, then reserves a path for information to flow around that.

In addition to the OSCARS website, some users can also make bandwidth reservations with either the TeraPaths or LambdaStation systems. Both were developed with support from ASCR, and are deployed at several universities and DOE laboratories across the country.

“If you think of local area networks (LANs) as a virtual cities and computers as the buildings within them, then ESnet’s SDN is the highway system that connects those cities,” says Yu. “TeraPaths and LambdaStation are planners that dynamically negotiate with OSCARS to reserve your highway bandwidth and navigate your dataset through the city streets to ensure you make the highway reservation. When combined with OSCARS, these systems guarantee users a dynamic 'end to end' data delivery service."

According to Guok, it used to take three months, 13 network engineers, 250 plus e-mails and 20 international conference calls to set up an inter-continental virtual circuit between the National Institute of Nuclear and Particle Physics in France and the Fermi National Accelerator Laboratory in Chicago.

“With OSCARS and collaborative projects, we can establish this link in 10 minutes, 10 plus e-mail notifications, zero conference calls and one user,” says Guok.

Because a user's request will traverse multiple networks to reach its destination, ESnet engineers are collaborating with several research and education network providers to ensure that OSCARS is compatible with a variety of network protocols. The consortium, called DICE, includes the Delivery of Advanced Network Technology to Europe (DANTE), Internet2, the California Institute of Technology's LHCNET, and ESnet.

“There are no guarantees with the Internet. When you shoot off an email, you have no idea when it will reach the recipient. This usually isn't a big problem. However, if you are a researcher relying on a valuable but limited supercomputer allocation to make a scientific breakthrough, you need a guarantee that your materials will reach the machine on-time,” says Guok. “OSCARS provides that guarantee.” 

For more information about OSCARS, please visit: