An automatic cache cooperative environment using ICP

Internet Cache Protocol (ICP) is useful for constructing a cooperative cache environment on the Internet. The proxy servers exchange ICP queries and replies in order to share the cached objects with others. However, the required bandwidth of the ICP procedure in the cooperative environment is fixed no matter how high or low the ICP hit rate is. We propose a querying filter mechanism to select proper ICP queries before sending them out. With the querying filter scheme, every proxy server builds a status table to store favorite Web hosts of its neighbors. When the original hosts are requesting, those objects will be delivered freely in order to keep the ICP hit rate stable. Other queries have to be filtered for decreasing additional traffic cost. By doing so the unqualified queries will be filtered and the network bandwidth can be saved; this eventually raises the utilization of the ICP mechanism.