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