Content delivery system, control apparatus, and content delivery method

A content delivery method, which is used in a content delivery system including a packet forwarding apparatus(es) that forwards a plurality of contents delivered from a delivery server apparatus on the Internet and a plurality of cache servers that are arranged for or connected to the packet forwarding apparatus(es) and that temporarily store at least some of the plurality of contents, the content delivery method comprising:

• by a control apparatus controlling the plurality of cache servers, collecting an access frequency of each of the at least some of the contents from the plurality of cache servers;
• arranging contents whose access frequency is equal to or higher than a predetermined threshold in the plurality of cache servers in accordance with a predetermined arrangement;
• and
• arranging the other contents in the plurality of cache servers in accordance with access frequencies of the other contents.