Experiencing slow iTunes download speeds, and/or frequent movie buffering on your Apple TV, with no apparent reason? Your DNS settings may be the culprit. A couple of savvy users affected by slow iTunes speeds recently realized that they all shared the same DNS settings, as they all opted to use centralized DNS services such as Google DNS, UltraDNS or OpenDNS, instead of using their internet service provider default DNS server. The DNS (domain name system) is a suite of computers designed to help you find your way on the web: for instance, when you type http://www.iosnoops.com in your favorite browser, the DNS tells your browser how to find our servers. When it comes to DNS, several options are available, as you can use the default DNS offered by your internet provider, or you can use centralized DNS services such as Google’s, believed by many to be faster and more secure than their default DNS. So what’s the issue? Services such as Google DNS are centralized, and tend to pose problems with distributed content delivery networks, used by folks like Apple to deliver your content. Akamai, the content delivery network used by Apple to send iTunes content to your home, uses your DNS settings to figure out your rough location, and redirects you to the nearest and fastest server based on this information. When users choose to use centralized DNS services, the content delivery network cannot easily figure out which server is the most suitable, and in some cases, Akamai will send your request to a server located far from you. The result? Slow speeds, and lots of latency. If you experience the issue, and happen to use a centralized DNS service, simply revert your router and/or computers back to their original DNS settings. This information is usually available via your router, or on your internet service provider’s website.