Have you ever noticed that large downloads go quickly on your broadband Internet connection but websites still seem to load at dial-up speeds? I have a 10Mb/s DSL connection which–in theory anyway–is about 182 times more bandwidth than a 56k modem. Yet loading my Facebook profile took can take up a minute, which by todays standards feels like a lifetime. The problem was caused by slow DNS servers at my ISP and I solved the problem using Open DNS.
The Difference Between Downloading a Large File and Viewing a Website
When you download a single large file from the Internet like a music album or an episode of your favorite show, the download is a single continuous stream of information, all originating from the same location. But have you ever noticed that when you view a website, all of the sudden your web browser’s status bar starts going a little crazy? That’s because when you view a website, it needs to download not just the “web page” but all of the supporting images, videos, and other external resources. Each resource is downloaded individually, and they may or may not be downloaded from the same central location.
Why DNS May Become a Bottleneck
When a webpage is requested the domain name (like google.com) must be translated to a numerical address (called an IP Address) which can be understood by the computers and devices that make up the Internet. This translation is done by a special service called DNS which your Internet Provider automatically assigns to your Internet connection. DNS must be consulted each time a resource is requested, hence if a web page contains 20 supporting resources DNS could possibly be called 21 times to translate names to numerical addresses. If your Provider’s DNS servers become bogged down this can increase the time it takes for resources needed by a web page to be located.
OpenDNS to the Rescue
I discovered a service tonight called OpenDNS that hosts free DNS servers that you can easily configure on your own Internet Connection. If you find that your web surfing seems sluggish, visit OpenDNS and follow their instructions for using their service on your computer. If you find that it doesn’t help, it’s easy to switch back to your ISP’s DNS servers.