A process for opening and reading a file over a network, including a WAN. An edge file gateway receives a request from an application to open a file cached with the edge file gateway at one point on a network and stored on a file server connected to a central server at another point on the network. The edge file gateway forwards the request to open the file to the central server, along with any offsets and lengths stored from any previous requests to read the file. The central server responds by sending any file data described in the offsets and lengths to the edge file gateway. When the edge file gateway receives a read request, the edge file gateway stores the offset and length for the request, if a predefined storage limit is not exceeded, and attempts to satisfy the request from cached file data.