Monday, December 15, 2014
Recently the Google Public DNS team, in collaboration with Akamai, reached an important milestone: Google Public DNS now propagates client location information to Akamai nameservers. This effort significantly improves the accuracy of approximately 30% of the location-sensitive DNS responses returned by Google Public DNS. In other words, client requests to Akamai hosted content can be routed to closer servers with lower latency and greater data transfer throughput. Overall, Google Public DNS resolvers serve 400 billion responses per day and more than 50% of them are location-sensitive.
DNS is often used by Content Distribution Networks (CDNs) such as Akamai to achieve location-based load balancing by constructing responses based on clients' IP addresses. However, CDNs usually see the DNS resolvers' IP address instead of the actual clients' and are therefore forced to assume that the resolvers are close to the clients. Unfortunately, the assumption is not always true. Many resolvers, especially those open to the Internet at large, are not deployed at every single local network.
To solve this issue, a group of DNS and content providers, including Google, proposed an approach to allow resolvers to forw