Step 5. 
Content Downloading

The client identifies a desired file to download, and initiates a download request, which is received by Omneo P2P (5).  Technically, this request looks similar to a conventional HTTP GET request, except that the requested filename is actually a lengthy hash value, which identifies the file name, version, and source location of the content. When any P2P client in the network chooses to share content, the process of sharing the content generates the unique hash-value filenames that are used by FastTrack 2.0.  If the original content is changed in any way, the filename hash is automatically regenerated to reflect the changed content. Fresh content is thus automatically identified by the FastTrack 2.0 operational protocol, and recognized by Omneo P2P as part of the caching process.  Content refreshing, therefore, happens automatically as part of the normal caching process. (5a, 5b.)

Omneo P2P Cache Refresh and Content Delivery