Abstract: The disclosed apparatus and method include transmitting and receiving frame(s) to/from another transmission apparatus, storing header information of user frames that are currently being transmitted to the other transmission apparatus, detecting whether the maintenance frame was received, splitting user frames and interrupting the transmission processing of the user frames, adding to subsequent user frames combination information, performing a transmission processing on response maintenance frames, resuming transmission processing of the subsequent user frames, and adding combination information and header information.

Abstract: A frame transmission device which does not require a separate supervisory line and enables supervisory frames to efficiently enter subscriber traffic for transmission without securing a fixed bandwidth. A supervisory token computing section gives supervisory frames supervisory tokens as permission to transmit within a minimum bandwidth. Subscriber token computing sections give subscriber frames subscriber tokens as permission to transmit within respective set transmission bandwidths. A best-effort token computing section gives the frames best-effort tokens as permission to transmit by using an extra bandwidth. The supervisory or subscriber tokens are given to read frames from a supervisory queue or subscriber queues, and if a frame queue length is smaller than or equal to the best-effort tokens remains in the queue, a queue read control section reads and outputs the remaining frames from the queue by using the extra bandwidth of best-effort tokens.

Abstract: A relay unit capable of avoiding the occurrence of simultaneous switching whatever data is received and thereby preventing malfunction of the device due to impulse noise, and a memory product having stored therein a computer program are provided. The relay unit includes a latch unit that temporarily stores converted parallel data; a determining unit that compares received data with subsequent data to be received subsequently and thereby determines whether to invert bits of data; and an inverting unit that invert bits of converted serial data. When the determining unit determines that bit-inverted parallel data is received as subsequent data, the determining unit transmits to the latch unit a signal instructing to prohibit from storing temporarily the received subsequent data and transmits to the inverting unit a signal instructing to invert bits of data.

Abstract: An uninterruptible transfer can be realized during a line failure in a transmission system performing a packet transmission between transmitting apparatuses connected via a plurality of lines. In a method for realizing the uninterruptible transfer, test packets including information of the number of packets received from the transmitting apparatus of a destination are periodically sent to the transmitting apparatus of a source. The transmitting apparatus of the source compares the received information of the number of packets included in the received test packets with the number of packets sent out to the transmitting apparatus of the destination via one line. When the comparison shows a disagreement between the number of the received packets and the number of the sent-out packets, packets corresponding to the disagreement are resent to the transmitting apparatus of the destination via another line.

Abstract: A frame transmission device which does not require a separate supervisory line and enables supervisory frames to efficiently enter subscriber traffic for transmission without securing a fixed bandwidth. A supervisory token computing section gives supervisory frames supervisory tokens as permission to transmit within a minimum bandwidth. Subscriber token computing sections give subscriber frames subscriber tokens as permission to transmit within respective set transmission bandwidths. A best-effort token computing section gives the frames best-effort tokens as permission to transmit by using an extra bandwidth. The supervisory or subscriber tokens are given to read frames from a supervisory queue or subscriber queues, and if a frame queue length is smaller than or equal to the best-effort tokens remains in the queue, a queue read control section reads and outputs the remaining frames from the queue by using the extra bandwidth of best-effort tokens.