1. Content Delivery Networks

3. History Early 1990s sees 100% growth in internet traffic per year 1994 o Netscape forms and releases their first browser o Yahoo created o W3C founded 1995 - 1996, internet traffic grows by 1000% per year 1995 o Java released o Internet Explorer released 1996 o Google created at Stanford o WebTV Introduced 1998 - Akamai forms 1999 - Akamai signs a deal with Apple to deliver QuickTime content

4. Problems Files keep getting larger Internet Usage keeps increasing Flash crowds/Slashdot effect The distance between end points causes added latency

5. Solutions Caching o Keep things in memory o Dynamic content is reused with TTL rather than regenerated o Caching proxy servers Server Clusters o Load balancer routes to servers in a cluster, usually based on load Edge Nodes o Requests are routed to edge nodes based on location

6. Request Routing Layer 4 Load Balancer o Does not look at request content o Often knows the status of the servers it routes to Layer 4-7/Web/Application Switch o Inspects request content o Can do some processing, such as SSL o Can be cookie aware DNS Based Routing o Resolves a domain name to different IP addresses Link Load Balancing o Often there is more than one route to a host, always make sure to select the best one

7. Origin Server Replicated Edge Servers Clients

8. Akamai Over 61,000 servers in over 70 countries Commodity hardware with distributed software http://www.akamai.com/ Data Visualization Tour Akamai's NOC

9. P2P CDN Pros o Efficient use of bandwidth o Lower Cost Cons o No QoS o Requires cooperation from clients o Not good for unpopular things

10. P2PTV

11. BitTorrent