October 11, 2011, 4:41 PM — A new vendor-sponsored study of the 1,000 biggest websites quantifies how much better third-party managed service providers are doing at operating DNS services across the Internet cloud than enterprises that run this critical network service themselves.
U.S. websites that operate their own DNS services experience availability that is significantly lower -- averaging minutes of costly downtime per day -- when compared to sites that outsource their DNS.
The study was conducted by ThousandEyes, which calculated the minimum, maximum and average DNS availability of the Alexa 1,000 websites during the second quarter of 2011. The study shows that U.S. managed service providers offer higher availability in all three categories when compared to U.S. companies with internally managed DNS.
The study was commissioned by Verisign, which sells managed DNS services.
Websites that used third-party managed DNS providers did not experience any total outages during the course of the study, while self-managed sites were shown to have a higher propensity to experience near to total outages.
Managed service providers offer better availability because they have more data center locations scattered across the Internet to answer DNS queries closer to users. Additionally, these providers use what's called an anycast DNS resolution service, which means there is always a server available somewhere to respond to DNS queries. The study identified one DNS provider that uses both anycast and unicast DNS resolution, which provides the optimal combination of performance and reliability for DNS queries and responses.
"Few enterprises have the resources and expertise to set up such extensive systems for their internally managed DNS," the study said. "This may explain the discrepancy and is an indication that most businesses with internally managed DNS would benefit from a secondary managed DNS service that can act as a backup to serve traffic to their websites in the event that the primary DNS management tool becomes unavailable."
Another reason third parties offer higher availability with their cloud-based DNS services is that they can afford dedicated network engineers who specialize in DNS.