Techniques for caching media data, including streaming media data, using
content-sensitive identifiers. The content-sensitive identifiers enable a
caching proxy or a caching server to unambiguously determine the version
or contents of media data cached by the caching proxy for a particular
data pointer or data reference (e.g., a URL) such that an appropriate
version of the media data can be served to a requesting client system in
an efficient and economical manner.