Increasingly popular social-networking sites such as MySpace, YouTube and Facebook are accounting for such huge volumes of DNS queries and bandwidth consumption that carriers, universities and corporations are scrambling to keep pace.

The trend is prompting some network operators to upgrade their DNS systems, while others are blocking the sites altogether. Moreover, the ‘MySpace Effect’ is expected to hit many more nets soon, as these network-intensive interactive features migrate from specialty sites to mainstream e-commerce operations and intranets.

"Social media is not just going to be in pure-play sites like MySpace and Facebook. It's going to become increasingly prevalent across retailers, media and entertainment," said Mike Afergan, CTO of Akamai, a content delivery network company that supports MySpace, Facebook and Friendster. "It drives a lot more requests and a lot more bit-traffic across these networks."

The demanding nature of social-networking sites was highlighted in May when the Department of Defense announced it was blocking worldwide access to 13 websites, including MySpace and YouTube.

"The Commander of DoD's Joint Task Force, Global Network Operations has noted a significant increase in use of DoD network resources tied up by individuals visiting certain recreational internet sites," Army General B.B. Bell said in a memo. "This recreational traffic impacts our official DoD network and bandwidth availability, while posing a significant operational security challenge."

The Defense Department began blocking access to these sites on May 14 on its unclassified IP network, which is called NIPRNET for Non-secure Internet Protocol Routed Network.

The military isn't the only organisation to notice how taxing these sites are on network resources.

"One of the things we're hearing more and more from carriers is that social-networking sites like MySpace and YouTube are contributing to an exponential increase in DNS traffic," said Tom Tovar, president and COO of Nominum, which sells high-end DNS software to carriers and enterprises.

Social-networking sites create large volumes of DNS traffic because they pull content from all over the internet. Most of these sites use content-delivery networks to extend the geographical reach of their content so users can access it closer to home.

"A single MySpace page can have anywhere from 200 to 300 DNS lookups, while a normal news site with ads might have 10 to 15 DNS lookups," Tovar said. "It's an exponential increase."

Virgin Media, the UK cable operator with 10 million subscribers (including 3.5 million broadband users), has found that the amount of DNS traffic generated by social-networking sites has grown dramatically in the past 10 months. YouTube and Facebook traffic has doubled in that timeframe but still represents a fraction of Virgin Media's overall DNS traffic. YouTube grew from 0.5 percent to 0.75 percent of the carrier's DNS traffic, while Facebook grew from 0.5 percent to 1 percent.
In contrast, MySpace now represents 10 percent of Virgin Media's DNS traffic, up from 7.2 percent last fall.