DNS - DNS Protocol Extension: A Boon to CDNs

Since a group of DNS and content delivery providers – including Neustar/UltraDNS and Google – published a proposal to extend the DNS protocol, many question whether the savings justify the change. And one Gartner (News - Alert) analyst contends that the Google proposal is a real boon to CDNs.

According to Google officials, the DNS protocol is an important part of the Web’s infrastructure, serving as the Internet’s phone book: Every time you visit a Web site, your computer performs a DNS lookup. Complex pages often require multiple DNS lookups before they start loading, so your computer may be performing hundreds of lookups a day.

By returning different addresses to requests coming from different places, DNS can be used to load balance traffic and send users to a nearby server, explained Google’s (News - Alert) Wilmer van der Gaast and Carlo Contavalli on behalf of the Google Public DNS team in this blog entry.

According to Gartner’s Lydia Leong, Google’s proposal is a boon to CDNs as well as anyone else that relies upon DNS for global load-balancing solutions.

“A couple of weeks ago, Google and UltraDNS (part of Neustar) proposed an extension to the DNS protocol that would allow DNS servers to obtain the IP address of the end-user who originally made the request,” wrote Leong. “…And the DNS servers of things like CDNs use the location of the DNS query to figure out where the user is, which means that they actually return an optimal server for the resolver’s location, not the user’s.”

According Leong, in the ecosystem where it’s supported, the enhancement will also give “a slight performance boost to CDNs with more local footprint, by helping to ensure that the local cache is actually more local to the user.”