New Algorithm Significantly Boosts Routing Efficiency of Networks

Aug 18, 2008 By Paul K. Mueller
The XL algorithm developed by computer scientists at UC San Diego significantly outperforms standard link-state and distance-vector algorithms, speeding routing in computer and communications networks.

(PhysOrg.com) -- A time-and-money-saving question shared by commuters in their cars and networks sharing ever-changing Internet resources is: "What's the best way to get from here to there?"

A new algorithm developed by computer scientists at the University of California, San Diego helps answer that question, at least for computer networks, and it promises to significantly boost the efficiency of network routing.

Called XL, for approximate link state, the algorithm increases network routing efficiency by suppressing updates from parts of the system – updates which force connected networks to continuously re-calculate the paths they use in the great matrix of the Internet.

"Routing in a static network is trivial," say the authors in their paper, which will be presented at this week's ACM SIGCOMM conference. "But most real networks are dynamic – network links go up and down – and thus some nodes need to recalculate their routes in response."

The traditional approach, said Stefan Savage, professor of computer science at UC San Diego, "is to tell everyone; flood the topology change throughout the network and have each node re-compute its table of best routes – but that requirement to universally communicate, and to act on each change, is a big problem."

What the team did with their new routing algorithm, according to Savage's student Kirill Levchenko, was to reduce the "communication overhead" of route computation – by an order of magnitude.

"Being able to adapt to hardware failures is one of the fundamental characteristics of the Internet," Levchenko said. "Our routing algorithm reduces the overhead of route re-computation after a network change, making it possible to support larger networks. The benefits are especially significant when networks are made up of low-power devices of slow links."

The real technical innovation of their work, said another of the authors, Geoffrey M. Voelker, "is in how information about changes in the network is propagated. The XL routing algorithm propagates only some updates, reducing the number of updates sent through the network."

They meet the "central challenge" of determining which updates are important and which can be suppressed by using three rules for update propagation, said team member Ramamohan Paturi. "The rules ensure that selected routes are nearly as good as if complete information about the network were available," he said, "but at a fraction of the overhead required for maintaining such a state of perfect knowledge."

The computer scientists also believe that there are "significant opportunities" to improve the efficiency of link-state routing even further. They look forward to discovering an algorithm that improves on their Approximate Link work with similar boosts in efficiency.

Source: University of California - San Diego

Explore further: Google's Street View address reading software also able to decipher CAPTCHAs

add to favorites email to friend print save as pdf

Related Stories

Optimising the future with mathematics

Mar 11, 2014

How will science address the challenges of the future? In collaboration with Australia's chief scientist Ian Chubb, we're asking how each science discipline will contribute to Australia now and in the fu ...

Startup Instacart hopes to dominate grocery delivery

Jan 30, 2014

On a mission to prove that consumers will pay to have bread and milk delivered to their front door, Instacart is expanding across the country as it aims to right the wrongs of years of failed grocery delivery ventures.

Recommended for you

Ant colonies help evacuees in disaster zones

Apr 16, 2014

An escape route mapping system based on the behavior of ant colonies could give evacuees a better chance of reaching safe harbor after a natural disaster or terrorist attack by building a map of showing the shortest routes ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

pup
not rated yet Sep 08, 2008
great, now show me the C code, and make sure to aptimise it for x86-sse3/PPC=Altivec SIMD from day one.

http://www.freeve..._updated

http://bjacob.liv...600.html

More news stories

Venture investments jump to $9.5B in 1Q

Funding for U.S. startup companies soared 57 percent in the first quarter to a level not seen since 2001, as venture capitalists piled more money into an increasing number of deals, according to a report due out Friday.

White House updating online privacy policy

A new Obama administration privacy policy out Friday explains how the government will gather the user data of online visitors to WhiteHouse.gov, mobile apps and social media sites. It also clarifies that ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Scientists tether lionfish to Cayman reefs

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

Leeches help save woman's ear after pit bull mauling

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...