Abstract: A mobile station-side acquirer acquires the MTU value notified by a base station-side notifier and stores the acquired MTU value in a mobile station-side memory. A mobile station-side transmitter transmits data to a destination with the data size set to be smaller than or equal to the MTU value stored in the mobile station-side memory. A base station-side acquirer acquires the MTU value of the transmission path and stores the acquired MTU value in a base station-side memory. The base station-side notifier notifies the mobile station of the MTU value stored in the base station-side memory.

Abstract: An IP network communication system which applies encryption with a reduced processing delay caused by a CPU load which is increased by the application of IPsec etc., and with reduced degradation of data transmission efficiency in a network, is provided. The IP network communication system having a security function includes an encryption processing part to encrypt a predetermined area range of one packet to be transmitted, and not to encrypt a residual area of the one packet; and a transmission part to transmit the packet encrypted by the encryption processing part through a tunnel for encryption.

Abstract: A mobile station-side acquirer acquires the MTU value notified by a base station-side notifier and stores the acquired MTU value in a mobile station-side memory. A mobile station-side transmitter transmits data to a destination with the data size set to be smaller than or equal to the MTU value stored in the mobile station-side memory. A base station-side acquirer acquires the MTU value of the transmission path and stores the acquired MTU value in a base station-side memory.

Abstract: A DMA transferring system with a plurality of devices, the devices being connected to each other by a data transmission line, where DMA transferring is performed among the devices includes a DMA controller provided in each of the devices performing the DMA transferring and configured to implement a DMA command of write transferring. The DMA controller includes a part configured to, in a case where a DMA command of read transferring is selected, send the DMA command of read transferring to the DMA controller of one of the devices sending data of the read transferring; and a part configured to perform DMA transferring by changing the DMA command of read transferring received from the DMA controller of another of the devices to a DMA command of write transferring in the one of the device sending the DMA command.

Abstract: A network device with bandwidth usage control functions using a leaky bucket algorithm to provide a traffic service conforming to given user parameters. A leaky bucket counter produces a new leaky-bucket (LB) count at predetermined cell slot intervals by adding an output rate parameter to the previous count, and then by subtracting therefrom a full rate parameter if a cell output request signal is active. An upper limit calculator determines an upper limit for such LB count values, and a count modifier applies this upper limit, thereby producing a modified LB count. When the modified LB count from the count modifier equals or exceeds an output reference value, a comparator activates an output timing signal, which permits transmission of a pending cell in a buffer.

Abstract: A network device with bandwidth usage control functions using a leaky bucket algorithm to provide a traffic service conforming to given user parameters. A leaky bucket counter produces a new leaky-bucket (LB) count at predetermined cell slot intervals by adding an output rate parameter to the previous count, and then by subtracting therefrom a full rate parameter if a cell output request signal is active. An upper limit calculator determines an upper limit for such LB count values, and a count modifier applies this upper limit, thereby producing a modified LB count. When the modified LB count from the count modifier equals or exceeds an output reference value, a comparator activates an output timing signal, which permits transmission of a pending cell in a buffer.