A data transfer system is described herein that allows data to be sent directly between two computing devices at the request of a third party client computer. The system allows a third party to initiate data transfers between computers in a network file system. This results in a significant speed increase because little to no data travels over the third party's potentially slower connection. The data transfer system provides a mechanism to determine if the direct transfer would be more efficient than two separate read and write operations, based on measurements of bandwidth and latency between each computing device. The data transfer system provides support for the source server to compress the data and the destination server to decompress the data at the direction of a third party client to further save network bandwidth.