Issue link: https://read.uberflip.com/i/1146286
Content Delivery Networks | 19 Content Delivery Networks A content delivery network (CDN) is a collection of web servers distributed across multiple locations to deliver content to users more efficiently. This efficiency is typi- cally discussed as a performance issue, but it can also result in cost savings. When optimizing for performance, the server selected for delivering content to a specific user is based on a measure of network proximity. For example, the CDN may choose the server with the fewest network hops or the server with the quickest response time. Some large Internet companies own their own CDN, but it's cost effective to use a CDN service provider. Akamai Technologies, Inc. is the industry leader. In 2005, Akamai acquired Speedera Networks, the primary low-cost alternative. Mirror Image Internet, Inc. is now the leading alternative to Akamai. Limelight Networks, Inc. is another competitor. Other providers, such as SAVVIS Inc., specialize in niche mar- kets such as video content delivery. Table 2-1 shows 10 top Internet sites in the U.S. and the CDN service providers they use. You can see that: • Five use Akamai • One uses Mirror Image • One uses Limelight • One uses SAVVIS • Four either don't use a CDN or use a homegrown CDN solution Table 2-1. CDN service providers used by top sites Web site CDN http://www.amazon.com Akamai http://www.aol.com Akamai http://www.cnn.com http://www.ebay.com Akamai, Mirror Image http://www.google.com http://www.msn.com SAVVIS http://www.myspace.com Akamai, Limelight http://www.wikipedia.org http://www.yahoo.com Akamai http://www.youtube.com