Inadequate client awareness of caches. Lack of use of MIME header. Lots of rule-bases. Lack of support of protocols like ftp and Gopher. Explain why or why not.
Caches help to reduce user perceived latency and they save bandwidth.
They help to reduce network congestion. Servers will not be overloaded and hence their scalability will improve. However, the hit ratio can be improved by using better caching algorithms, maybe even domain specific ones. If there are a small number of frequently used objects, then these could be kept in main memory to speed up access. Local caches can be used if the hierarchical design is not so useful.