Patent application number | Description | Published |
20090122800 | FRAME TRANSFER ROUTE CONFIRMATION METHOD, NODE, FRAME TRANSFER ROUTE CONFIRMATION PROGRAM AND FRAME TRANSFER ROUTE CONFIRMATION SYSTEM - The frame switching unit | 05-14-2009 |
20090257458 | CLOCK SYNCHRONIZATION SYSTEM - A clock synchronization system includes a master node; a PSN (Packet Switched Network); and a slave node configured to synchronize a recovery clock signal in the slave node with a clock signal in the master node by using packets periodically received from the master node through the PSN. The slave node includes: a buffer section having a buffer and configured to temporarily store the packets received from the master node in the buffer, to monitor and output a buffer accumulation amount, and to output data of the packets from the buffer in response to the recovery clock signal; a maximum extracting section configured to receive the buffer accumulation amount from the buffer and to extract a maximum value for each time period from the buffer accumulation amount; a control section configured to generate a control voltage such that the maximum values from the maximum extracting section are held at a reference value; and a VCO (Voltage Controlled Oscillator) configured to adjust a frequency of the recovery clock signal based on the control voltage from the control section. | 10-15-2009 |
20100232322 | NODE, NETWORK SYSTEM, FRAME TRANSFER METHOD, AND FRAME TRANSFER PROGRAM - For eliminating a reduction in throughput in a network as a whole according to optimum path transfer technique which is the expansion of spanning tree protocol, a frame switching unit of the network has an STP control unit for, when a port state of a spanning tree is changed, notifying a table control unit of an identifier of the spanning tree and a port number of a predetermined port among the respective ports, the table control unit for setting, in a forwarding table storage unit, a received port number of a predetermined port as an output port in an entry in which a node ID is equivalent to a spanning tree identifier, and a table search unit for determining an output destination from among output ports obtained by acquisition of received frame information from a frame analysis unit. | 09-16-2010 |
20100309934 | CLOCK SYNCHRONIZATION SYSTEM, ITS METHOD AND PROGRAM - The clock synchronization accuracy between a master node and a slave node is stably measured. The slave node synchronizes its own clock with the clock of the master node by means of the packets transmitted from the master node. It reproduces the clock of the slave node by means of the transmitted packets, accumulates information on the transmitted packets and the clock of the slave node and performs clock synchronization on the basis of the accumulated information. | 12-09-2010 |
20110228834 | PACKET-FILTER-USED CLOCK SYNCHRONIZATION SYSTEM, APPARATUS, METHOD AND PROGRAM THEREOF - A clock synchronization system synchronizes a clock of a slave node with a clock of a master node. The master node includes a packet transmitting unit that transmits a packet including a time stamp (TS) to the slave node. The slave node includes: a packet receiving unit that receives the packet transmitted from the master node; a packet filter unit that calculates as a value of delay of the packet a difference between a TS on the clock of the slave node when the packet is received and the TS of the packet received, corrects the value of the delay of the packet or a threthold for the delay of the packet, and performs filter processing on the packet received from the packet receiving unit based on the value of the delay of the packet and the threshold for the delay of the packet; and a phase synchronization unit that outputs the clock of the slave node based on the TS included in the packet employed. | 09-22-2011 |
20120020232 | COMMUNICATION APPARATUS, COMMUNICATION SYSTEM AND COMMUNICATION METHOD - A communication apparatus including: a counter storage unit storing a reception counter value of the apparatus when a specific frame is received; a measurement unit measuring the number of frame losses occurring between the apparatus and the preceding apparatus on the basis of the reception counter value of the apparatus, a transmission counter value of a source apparatus of the specific frame included in the specific frame and the total number of frame losses between the source apparatus and the preceding apparatus of the apparatus, when the specific frame is received; a transmission unit transmitting the specific frame; and a frame control unit adding, to the specific frame, loss information associating the number of frame losses occurring between the apparatus and the preceding apparatus with an identifier of the apparatus and forwarding the specific frame to the transmission unit, when the frame loss occurs, and forwarding the specific frame to the transmission unit without adding the loss information to the specific frame, when no frame loss occurs. | 01-26-2012 |
20120113820 | CONGESTION DETECTING METHOD AND COMMUNICATION NODE - An inspection signal to inspect forward-path or return-path communication, is transmitted from a reference node of a network. A response signal is transmitted in a priority class from a node of a forward path to the reference node. In the case of inspection of return-path communication, a replica of the response signal is transmitted in a non-priority class from the node of the forward path to the return path, and the node that receives the replica of the response signal transfers the replica in a priority class to the reference node. In the case of inspection of forward-path communication, a replica of the inspection signal is transmitted in a non-priority class from the node of the forward path to the forward path, and a replica of the response signal is transmitted in a priority class from the node that receives a replica of the inspection signal to the reference node. | 05-10-2012 |
20120219003 | NODE, A MONITORING MANAGEMENT METHOD USED FOR IT, AND A TRANSFER SYSTEM, AN INPUT CIRCUIT AND AN OUTPUT CIRCUIT USING IT - [Issues] To provide a node (transfer device) which can process an OAM frame within an output line card. | 08-30-2012 |
20130028272 | COMMUNICATION APPARATUS, PACKETIZATION PERIOD CHANGE METHOD, AND PROGRAM - To provide a communication apparatus and a packetization period change method that allow a packetization period/TDM period to change during a service of a TDM-PW system without affecting the service traffic, there is provided a communication apparatus that receives packetized data converted from TDM data, including a period information detection unit, a jitter buffer that stores the packetized data for a certain period of time, and a jitter buffer capacity control unit. The period information detection unit extracts packetization period information indicating a period to packetize TDM data contained in the received packetized data and acquires a TDM period to time-division multiplex the packetized data based on the packetization period information. The jitter buffer capacity control unit receives the acquired TDM period and controls a capacity of the jitter buffer in accordance with the TDM period. | 01-31-2013 |
20130170390 | DELAY MEASUREMENT SYSTEM AND DELAY MEASUREMENT METHOD, AS WELL AS DELAY MEASUREMENT DEVICE AND DELAY MEASUREMENT PROGRAM - The present invention measures 1-way delay without equipping all nodes with special functionality in a situation in which time has not been synchronized. The delay measurement system of the present invention has a transmission origin node and a transmission destination node which is connected to the transmission origin node through a network including relay nodes, and measures the delay time from the transmission origin node to the transmission destination node direction, wherein the transmission origin node generates a clock. On the basis of the generated clock, delay measurement packets are generated at regular periods. The generated delay measurement packets are transmitted to the transmission destination node. The transmission destination node selects the delay measurement packets from among the received frames. The delay received by the delay measurement packets in the network between the transmission origin node to the node itself is measured. | 07-04-2013 |
20140146686 | TRANSMISSION SYSTEM, TRANSMISSION DEVICE, PACKET LOSS RATIO MEASUREMENT METHOD, AND PACKET LOSS RATIO MEASUREMENT PROGRAM - In a transmission system capable of measuring packet loss ratio between arbitrary devices upon a transmission path without increasing bandwidth of an OAM frame band, a plurality of transmission devices which have been disposed upon a transmission path are provided with a frame analysis unit which receives data frames so as to analyze the type of the data frames, a count processing unit which stores the number of received frames included in the data frames into storage module provided beforehand, an output line end portion which outputs the data frames, and an OAM processing unit which calculates the packet loss ratio in the transmission path using the number of received frames. The frame analysis unit has a function which, if the data frames are OAM frames, copies the data frames and the OAM processing unit has a function which calculates the packet loss ratio using the copied OAM frames. | 05-29-2014 |
20140341044 | DIAGNOSTIC SYSTEM - A transmission source node transmits diagnostic frames where a TTL value is set to the number of hops that is counted until an intermediate node. A relay node decrements the TTL value of the received diagnostic frames, counts the number of diagnostic frames where the decremented TTL value is 0, and recognizes continuity between the transmission source node and the relay node based on the number of transmitted diagnostic frames transmitted from the transmission source node and the number of diagnostic frames where the decremented TTL value is 0. | 11-20-2014 |
20140347979 | COMMUNICATION SYSTEM, TRANSMISSION APPARATUS, COMMUNICATION APPARATUS, FAILURE NOTIFICATION METHOD, AND NON-TRANSITORY COMPUTER-READABLE MEDIUM STORING PROGRAM - An AIS management table | 11-27-2014 |