Internet could suffer more DNS ‘brown-outs’

Internet users in the US and potentially elsewhere face the prospect of slower Web page access and frustrating “broken” page links and outages unless leading internet service providers invest more in their DNS (Domain Name Server) infrastructure, Paul Mockapetris, the inventor of the DNS system has warned.

DNS, the system for naming internet locations (such as ‘ft.com’), is a critical component for most online tools. Internet communications - whether through a browser, e-mail or VoIP (voice-over-internet protocol) voice traffic - rely heavily on a well-functioning DNS service.

“The performance of DNS routinely impacts IP applications and ultimately the experience of the end user as they load web pages, receive emails, or place VoIP calls,” says Mr Mockapetris, who is chief scientist and chairman of Nominum, the internet infrastructure provider.

However he warns that new internet applications and the arrival of Microsoft’s Vista operating system could both add to the strain on existing DNS software potentially causing more internet service outages.

Microsoft Vista will ship later this year with a new version of internet addressing called IPv6 enabled by default which has the potential to more than double the amount of queries to the DNS, resulting in an additional slowing effect on DNS response time.

To back up his claims, Nominum commissioned a survey from VeriTest, the testing service of Lionbridge, to measure DNS performance of eight leading cable and telecommunications service providers in the US which is published on Thursday.

Among its findings, the survey reveals that US cable network operators appear to have a significant edge over their telecommunications rivals when it comes to their DNS performance.

The results from the survey show that DNS response time and the percentage of unanswered queries vary widely across providers. In addition, many service providers have inconsistent performance results depending on the date and time, with dropped query rates varying by more than a factor of ten and DNS response time growing from a few milliseconds to several seconds.

The report concludes: “Of all the providers measured in this test, Comcast DNS servers have the fastest average response time, the lowest dropped query rate, and the most consistent response.”

At the other end of the spectrum, Verizon’s DSL and Fios fibre optic services appear to have the slowest response times, “which proves that fibre optics on its own does not necessarily guarantee the fastest speed,” Mr Mockapetris says.

“While DNS might not have been an area of investment historically, service providers are realising that the performance of DNS routinely impacts IP applications and ultimately the experience of the end user.

If not addressed, consumers across the US will experience “internet brownouts,” or random slowdowns in the middle of their online experiences,” said Albert Gouyet, vice president of marketing at Nominum. “This survey demonstrates that service providers such as Comcast are clearly ahead in providing consumers with a market leading DNS service in the core of their network.”