2009
01.26

In response to another paper staff, Mike Rose, yes, DNS (Domain Name Service) choice may in fact make a difference in how fast your downloads may be. The case: Akamai.

First off, a rundown on DNS, aka Domain Name Service. The best way to describe the process, and the role of DNS servers, is a numerical rundown:

  1. Your type in a web address, which must be converted into an IP address (like 138.67.1.1) for your computer to connect to the website you want.
  2. Your computer sends out to a DNS server to get the IP address of the site you want, querying “up the ladder” if needed (if it doesn’t have the IP stored in its records).
  3. The DNS server sends the IP address of the server you want to connect to.
  4. Your browser contacts the server and goes along its merry browsing way.
This is somewhat of a simplification, however that’s the way DNS servers work.
Normally, the server IP addresses always are the same thing, and any DNS server is as good as the next, with the slight advantage given to servers closer to you (such as your ISP’s server). However in some instances this sin’t the case.
One instance is when there are several servers giving out the exact same content in several locations across the globe, so people can get to content faster. This is referred to as a Content Delivery Network, or CDN. The gold standard in CDNs: Akamai.
Akamai has tons of servers across the globe, as close to ISPs as possible. Each has a different IP address. So providers work with Akamai to put the closest server to customers in their DNS record. So if you use Comcast’s DNS servers in Denver and download something via Akamai (whether it’s comcast.net or Windows 7 via Microsoft) you’ll get the closest server, and thus the fastest speeds and the lowest network congestion, available (less wires to traverse means more capacity for other things on that part of the network).
So why would you want to use DNS servers other than your providers? Ads or speed…
Some providers, Qwest included, will now redirect mistyped URLs (web addresses) to their own search pages, complete with ads. While this might be useful, the service tends to be obnoxious since you have to opt out of it if you don’t want the service, and opening a search page instald of just returning a “website not found” error tends to mess up some internet software and hardware.
There’s also the speed issue; in some cases, providers’ DNS servers are overloaded, causing response times to be slow, bottlenecking your internet connection for surfing to a rather alarming degree. Third-party DNS servers usually don’t have this problem.
As a prime example, OpenDNS, a third-party DNS server, is both fast and (if you want it to be) ad- (and search page-) free. You can also tell it to filter out unwanted sites, or shortcut “http://webmail.mines.edu” to just “mail”. However OpenDNS servers don’t get the special Akamai treatment since they aren’t region-specific, so your Windows 7 downloads may be a bit “father away”, and thus slower.
If you didn’t know about all this DNS magic, or how it affects “Akamaized” content, no matter; it’s complex stuff that I only recently learned about via the good forum folks at DSLReports. But it’s nice to know if you want to have the fastest downloads from some places, like iTunes, Comcast.net or Windows 7′s beta program.
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