Patent ID: 9736076
Date: 2017-08-15
CPC Classifications: G06F,H04L

Claim:
1. A device server, capable of being connected to a client via a network and also being connected locally to a device for performing isochronous transfer, said device server comprising: a data buffer portion for buffering transfer data upon receiving an isochronous output transfer request from said client; and at least one driver; and wherein said device server changes operation of said at least one driver according to at least the following cases (1) to (3): (1) in a range of time starting from a state wherein the retention data volume of the data buffer portion reaches an upper limit threshold to a state wherein the retention data volume becomes lower than an intermediate threshold, an isochronous output transfer to said device at a predetermined transfer rate is performed and when the isochronous output transfer is completed, if there is a request a response thereto is not sent back to said client, upon receiving an isochronous output transfer request from said client, a transfer completion response is sent back to said client and the transfer data received is accumulated in said data buffer portion; (2) in a range of time starting from a state wherein the retention data volume of the data buffer portion is lower than the intermediate threshold to a state wherein the retention data volume reaches the upper limit threshold or reaches the lower limit threshold, an isochronous output transfer to said device at a predetermined transfer rate is performed and unconditionally sending back a transfer completion response to said client upon receiving an isochronous output transfer request from said client and the transfer data received is accumulated in said data buffer portion; (3) in a range of time starting from a state wherein the retention data volume of said data buffer portion reaches the lower limit threshold to a state wherein the retention data volume reaches the upper limit threshold, without performing an isochronous output transfer to said device and unconditionally sending back the transfer completion response to said client upon receiving an isochronous output transfer request from said client and the transfer data received is accumulated in said data buffer portion.