Abstract: A communication apparatus includes a memory storing relation information indicating a plurality of relationships between a plurality of packet loss rates and a plurality of throughputs of the data included in the packets at the another communication apparatus, and a processor configured to determine a first transmission rate of the packets transmitted from the communication apparatus to the another communication apparatus, a receiving rate of the packets at the another communication apparatus being a maximum value without a packet loss, select a packet loss rate among the plurality of packet loss rates, the throughput of the data corresponding to the selected packet loss rate being under a threshold, based on the first transmission rate and the selected packet loss rate, determine a second transmission rate higher than the first transmission rate, and transmit the packets from the communication apparatus to the another communication apparatus at the second transmission rate.

Abstract: A communication system includes a transmitter configured to transmit a packet, a repeater configured to impose a bandwidth limit on the packet, a receiver configured to receive the packet on which the bandwidth limit is imposed, and a control device configured to set, when a reception interval of reception packets received by the receiver is longer than a transmission interval of packets transmitted to the repeater, a transmission rate in the transmitter in accordance with the reception interval.

Abstract: A non-transitory computer-readable storage medium storing therein a communication control program for causing a computer to execute processing includes, executing a prescribed command at a specified transmission cycle, acquiring a start time at which the execution is started and an end time at which the execution is ended, performing the execution and the acquisition while changing the transmission cycle, and specifying a transmission cycle at which an error between a difference between the end time and the start time and the specified transmission cycle is within a prescribed range.

Abstract: A communication control device including: a memory, and a processor coupled to the memory and the processor configured to: transmit packets from the communication control device to a network device at each of a plurality of transmission rates, acquire a plurality of index values respectively indicating amounts of packet loss at the plurality of transmission rates, specify, among the plurality of transmission rates, a first transmission rate on which a corresponding index value among the plurality of index values has a dependence, and specify an upper limit of a vacant band between the communication control device and the network device based on the first transmission rate.

Abstract: A communication control device including: a memory, and a processor coupled to the memory and the processor configured to: transmit packets from the communication control device to a network device at each of a plurality of transmission rates, acquire a plurality of index values respectively indicating amounts of packet loss at the plurality of transmission rates, specify, among the plurality of transmission rates, a first transmission rate on which a corresponding index value among the plurality of index values has a dependence, and specify an upper limit of a vacant band between the communication control device and the network device based on the first transmission rate.

Abstract: A data transmitting device configured to transmit data to a data receiving device via a communication line, the data transmitting device determines, based on first bandwidth information indicating a first bandwidth of the communication line from the data transmitting device to the data receiving device and first load information indicating a first load of the data receiving device, whether a first process is to be executed on first data before the first data is transmitted to the data receiving device, when it is determined that the first process is to be executed, executes the first process on the first data, and transmits, to the data receiving device, the first data on which the first process is executed, and when it is not determined that the first process is to be executed, transmits the first data to the data receiving device without executing the first process.

Abstract: A communication device including: a memory, and a processor coupled to the memory and configured to: receive a connection request that requests a session, calculate a processing load on processing of an ongoing session, determine, when the processing load exceeds a threshold, each protocol for each of the requested session and the ongoing session based on a comparison of a first throughput and a second throughput, the first throughput being an estimated throughput when a first protocol is to be used for the requested session and the ongoing session, the second throughput being an estimated throughput when a second protocol is to be used for at least one of the requested session and the ongoing session, a processing load of the second protocol being smaller than a processing load of the first protocol, and process each of the requested session and the ongoing session using each determined protocol.

Abstract: A communication system includes: a communication apparatus; and a transmission apparatus configured to transmit a packet to be transmitted from the communication apparatus to a transmission destination, wherein the communication apparatus transmits, to the transmission apparatus, a first request signal for requesting a start of a communication with the transmission destination and a second request signal for requesting the start of the communication with the transmission destination with passing through the transmission apparatus, and wherein, when a request of the first request signal is permitted, the transmission apparatus notifies the communication apparatus of that a request of the second request signal is not permitted, and transmits the first request signal to the transmission destination, and the communication apparatus receives a response to the first request signal from the transmission destination and starts communication with the transmission destination without passing through the transmission ap

Abstract: A frame transmitting apparatus includes a transmitting unit which transmits, when a change is made to a value in a predetermined field of a frame, the frame including the predetermined field with the changed value a predetermined number of times in succession. A frame receiving apparatus includes a receiving unit which receives the frame and an acceptance processing unit which recognizes the value in the predetermined field of the received frame and conducts acceptance processing. The acceptance processing unit compares, when the value is different from a currently accepted value, the value with an expected value; accepts the value when the value matches the expected value; and accepts, when the value does not match the expected value, the value after receiving the same value the predetermined number of times in succession.

Abstract: At a node, a first receiver receives ring information from a first adjacent node. A second receiver receives ring information from a second adjacent node. A first transmitter transmits ring information obtained by adding first local ring information attached between the node and the second adjacent node to the ring information received by the first receiver, to the second adjacent node. A second transmitter transmits ring information obtained by adding second local ring information attached between the node and the first adjacent node to the ring information received by the second receiver, to the first adjacent node.

Abstract: A network setup method used in a ring network including a plurality of transmission equipments. The method includes: transmitting a frame in the ring network; causing each of the transmission equipments to write an identifier to the frame according to a specified rule; determining whether or not a plurality of identifiers written to the frame by the plurality of transmission equipments satisfy a specified condition; and causing each of the transmission equipments to obtain a corresponding identifier according to the specified rule from among the plurality of identifiers, when the plurality of identifiers satisfy the specified condition.

Abstract: A TCP node stores a congestion window size before congestion is detected, the congestion window size limiting the amount of data to be transmitted. If congestion is detected, the TCP node reduces a current congestion window size to a predetermined size. If path switching subsequently occurs after congestion is detected, the TCP node uses a round-trip time or bandwidth information of a path after switching to correct the congestion window size before congestion detection. The TCP node then changes the reduced congestion window size to the corrected size.

Abstract: An apparatus switches paths in a wavelength-multiplexing network in which a first number of wavelengths each used for a path to transmit an optical signal are multiplexed into an optical fiber. The apparatus includes an entire switching unit and a second number of individual switching units where the second number is smaller than the first number. The entire switching unit is configured to perform a path-switching process for switching a path, simultaneously on all the first number of wavelengths when failures have occurred for all the first number of wavelengths. The second number of individual switching units are each configured to perform the path-switching process individually on one of a third number of wavelengths included in the first number of wavelengths when at least one failure has occurred for the third number of wavelengths where the third numbers is smaller than the first number.

Abstract: A communication system includes a transmitter configured to transmit a packet, a repeater configured to impose a bandwidth limit on the packet, a receiver configured to receive the packet on which the bandwidth limit is imposed, and a control device configured to set, when a reception interval of reception packets received by the receiver is longer than a transmission interval of packets transmitted to the repeater, a transmission rate in the transmitter in accordance with the reception interval.

Abstract: A transmission apparatus includes a processor configured to recognize a number of working failures and a number of protection failures on a network for transmission of wavelength-multiplexed signal light, the number of working failures being the number of failures in signal light in wavelengths at a working entity and the number of protection failures being the number of failures in signal light in wavelengths at a protection entity, configured to perform path switching for each group of signal light in wavelengths that are different from each other and configured to select, when multiple failures occur, restoration processing, on a basis of the number of working failures and the number of protection failures.

Abstract: An information processor apparatus includes a memory which stores a program, and a processor, based on the program, configured to, detect a packet that is transmitted from a management device to a second node that is included in a second network, and that triggers a request packet transmitted from the second node to a first node that is included in a first network, by monitoring communication from the management device that manages the first node and the second node that obtains data from the first node through a third network, and execute a proxy request by transmitting the request packet to the first node when the packet is detected and a connection is made with the first network.

Abstract: A frame transmitting apparatus includes a transmitting unit which transmits, when a change is made to a value in a predetermined field of a frame, the frame including the predetermined field with the changed value a predetermined number of times in succession. A frame receiving apparatus includes a receiving unit which receives the frame and an acceptance processing unit which recognizes the value in the predetermined field of the received frame and conducts acceptance processing. The acceptance processing unit compares, when the value is different from a currently accepted value, the value with an expected value; accepts the value when the value matches the expected value; and accepts, when the value does not match the expected value, the value after receiving the same value the predetermined number of times in succession.

Abstract: A TCP node stores a congestion window size before congestion is detected, the congestion window size limiting the amount of data to be transmitted. If congestion is detected, the TCP node reduces a current congestion window size to a predetermined size. If path switching subsequently occurs after congestion is detected, the TCP node uses a round-trip time or bandwidth information of a path after switching to correct the congestion window size before congestion detection. The TCP node then changes the reduced congestion window size to the corrected size.

Abstract: A node apparatus in a ring network in which a protection path is provided that cycles around the ring network and transports a signal in a direction opposite to a signal transporting direction of the working path and in the event of a failure of the working path, a node apparatus adjacent to the failure loops back the signal flowing on the working path onto the protection path, the node apparatus comprising: allowable bandwidth storing unit which stores a maximum total bandwidth value, which represents the largest value among per-link total values of bandwidths that a plurality of working paths use on respective links connecting between the node apparatuses, as an allowable bandwidth for a shared path; and bandwidth control unit which controls the bandwidth of traffic flowing on the protection path, in accordance with the allowable bandwidth.

Abstract: An apparatus switches paths in a wavelength-multiplexing network in which a first number of wavelengths each used for a path to transmit an optical signal are multiplexed into an optical fiber. The apparatus includes an entire switching unit and a second number of individual switching units where the second number is smaller than the first number. The entire switching unit is configured to perform a path-switching process for switching a path, simultaneously on all the first number of wavelengths when failures have occurred for all the first number of wavelengths. The second number of individual switching units are each configured to perform the path-switching process individually on one of a third number of wavelengths included in the first number of wavelengths when at least one failure has occurred for the third number of wavelengths where the third numbers is smaller than the first number.