Traffic Properties, Client Side Cachability and CDN Usage of Popular Web Sites

Joachim Charzinski


Web traffic measurement and modeling has contributed to understanding the effect of Web traffic on Internet resources since the 1990s. In the past years, a number of new Web features such as content delivery networks (CDNs), increased amount of advertisement, personalization, usage tracking, client scripting, Web 2.0 style ``mashups'', have gained more and more importance. This paper uses directed measurements to assess the efficiency of client side caching for modern Web sites, investigating some of the modern Web features. As expected, we see that more than 50% of the average downstream traffic volume is saved when loading a page using client side caching. More unexpected results comprise the actual distribution of cache effectiveness, varying between extreme and no reduction of traffic, the cachability of ``Web bugs'' and the variance between sites in cachable image pixels and CDN based files.


Internet; Web sites; measurement; caching; Web bugs; graphics; traffic analysis