superfluous network traffic, studies, analysis etc.

Hi,

I'm wondering if anyone knows of any studies on how to identify
superfluous network traffic, problems with identifying superfluous
traffic on large anonymous networks, studies that show how much
superfluous network traffic may be present on the internet etc.
Definition of superfluous being access of resource from same ip
address when the resource has not been changed.

Context is ideas on a freecache/coral network type system.

Cheers,
Bryan Rasmussen