Google, OpenDNS deploy DNS tweak for faster browsing

Nearly 40 million 'Net users to benefit from proposed extension to DNS protocol

Nearly 40 million Internet users will experience faster Web browsing starting today, thanks to a protocol tweak being deployed by Google, OpenDNS and several content delivery networks that allows them to more precisely serve up content from the nearest available server.

Nearly 40 million Internet users will experience faster Web browsing starting today, thanks to a controversial protocol tweak being deployed by Google, OpenDNS and several content delivery networks that allows them to more precisely serve up content from the nearest available server.

Dubbed "The Great Internet Speedup,'' this cooperative effort involves deploying an extension to the Domain Name System, which is the underlying protocol that matches Internet domain names with corresponding IP addresses.

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Proponents of the DNS tweak say it will decrease the latency end users experience when accessing videos and other large files, and that it offers CDNs a better ways to scale up their networks.

"Our expectation is that [the speed up] is going to be fairly significant," says David Ulevitch, founder and CEO of OpenDNS, which has more than 30 million users, including consumers, schools, small businesses and enterprises such as Nike and Staples. "From a latency standpoint, we think this will reduce some lookups by hundreds of milliseconds. If you're in Singapore, it'll make sure that you are getting to a data center in Singapore versus Hamburg."

But others say the DNS protocol tweak creates architectural issues and privacy concerns, the latter stemming from the passing of parts of IP addresses in a DNS query. This change to the DNS protocol has been proposed as an experimental document to the Internet Engineering Task Force, but it hasn't been adopted yet by the standards-setting body.

The IETF's DNS Extensions working group has not decided whether this work should be undertaken, according to working group chairmen Andrew Sullivan and Olafur Gudmundsson.

"Some participants in the IETF DNS Extensions Working Group have reacted quite negatively to this proposal and its ancestors," Sullivan and Gudmundsson say in response to questions about the status of the document. "One set of objections have primarily circled around privacy concerns. Another set have been architectural concerns: This effort is mostly one to solve a problem caused by other DNS tricks that are themselves regarded as bad ideas (specifically, several of the DNS techniques used by Content Delivery Networks.)"

Internet service providers that have deployed the DNS protocol tweak include OpenDNS and Google Public DNS as well as several smaller CDNs such as BitGravity, CDNetworks, EdgeCast, Comodo and CloudFlare.

Ulevitch couldn't say exactly how much faster the Internet would appear to end users who access content through participating DNS and CDN providers.

"We don't have any specific numbers yet to share, but there's no scenario where [DNS resolution] gets worse for end users," Ulevitch says. "This only adds a few bytes of overhead, and it's not going to be added to all Internet traffic. ...These bytes have the potential for resulting in big improvements."

Google will use the DNS tweak to not only speed up its Google Public DNS service but also to serve up content faster on YouTube.

"Google is committed to making the Internet faster -- not just for our users, but for everyone," Dave Presotto, a distinguished engineer at Google, said in a statement. "We will do that any way we can, by improving protocols, browsers, client software, and networks."

The protocol tweak was outlined in a draft IETF document called Client Subnet in DNS Requests that was written by technical staff from Google, Verisign and Neustar. This proposal creates an optional extension to the DNS that would allow recursive and authoritative name servers to convey additional network information from the end user's IP address so that the content can be served up from the closest available server.

Ulevitch says this DNS protocol tweak helps CDNs deal with the Internet's insatiable thirst for speed. "This is solving an immediate pain point: CDNs need to be able to scale, and ISPs need to make efficient use of their bandwidth," he adds. "It's an incremental change, but it has the potential to be a tremendous improvement."

Ulevitch says the proposed DNS tweak could benefit enterprises, too, by speeding up the rate at which their employees can access Internet content and how quickly their Web content is available to their customers.

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Several of the largest CDNs -- including Akamai, Level 3 and Limelight Networks -- are missing from the Great Internet Speedup effort. But Ulevitch encourages these companies to get onboard with the effort.

"We want as many CDNs as possible, also as many ISPs," he says. "Enterprises could also turn on this [proposed standard] to get internal DNS benefits."

Speaking as DNS experts, rather than as IETF working group chairmen, Sullivan and Gudmundsson say they aren't sure that the DNS protocol tweak will end up resulting in a faster Internet.

"What it will really do is sometimes make some DNS answers better tailored for an end system," they say. "It is not clear whether that will have negative effects for applications other than the Web, but it might."

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Copyright © 2011 IDG Communications, Inc.

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