Abstract: Communication quality values such as delay times of packets transmitted and received within a packet network are measured, and a threshold value is calculated based on the measured communication quality values. Further, a management reference value is calculated based on the communication quality values of packets whose measured communication quality values are within a range based on the threshold value. A communication state is detected by comparing the measured communication quality values with the management reference value.

Abstract: A relay device which forwards a packet received from a first device to a second device, the relay device includes a detection unit that detects that the relay device has been in a specified state, a generation unit that generates a packet that contains information for identifying the relay device and information indicating that the relay device is in the specified state when the detection unit detects that the relay device has been in the specified state, and a transmission unit that transmits the generated packet to a specific transmission destination.

Abstract: A method of measuring packet loss rate and device thereof, includes intermittently capturing packets during a session, counting a capture success number indicating a number of the packets captured in every period of a time for capturing the packets, and a capturable number indicating a possible number of the packets to be captured during the period of time without loss, calculating a loss rate indicating a rate of losing the packets, according to the capture success number and the capturable number for every period of time and correcting the loss rate, by the measuring device, so that the loss rate gets larger accordingly as average of capturable numbers of respective periods of time is smaller.

Abstract: A system includes a unit transmitting test packets to a to-be-measured communication link at a first time interval, a unit transmitting burst loads each including a series of load packets to the communication link at a second time interval, a unit performing measurement of delay time periods in a manner that a plurality of test packets transmitted by varying elapsed time periods each from an instance of transmission of the burst load to an instance of transmission of the test packet are received from the communication link in a fluctuating time interval, a unit generating delay distributions indicative of packet occurrence frequencies in relation to a delay time period of the communication link in accordance with the measured delay time periods, and a unit calculating a network load in accordance with occurrence frequencies in a specific section of the generated delay distributions.

Abstract: The present invention includes a designating packet transferring step, a measurement packet transmitting step and a measurement packet collecting step. The designating packet transferring step is a step of transferring a designating packet in a target section for a communication performance measurement in the communication network, the designating packet designating a relaying apparatus which adds information to the measurement packet from among plural relaying apparatuses. The measurement packet transmitting step is a step of transmitting a measurement packet from one end of the target section. The measurement packet collecting step is a step of collecting the measurement packet transferred in the target section from among measurement packets which are transmitted in the measurement packet transmitting step.

Abstract: A communication relay device adds information to communication data without depending on a communication application of a communication terminal. The relay device (1) includes a relay control portion (13), a control information database (14), an adder portion (15) and a database for addition (16). The relay control portion (13) controls the adder portion (15) in accordance with information accumulated in the control information DB 14. The adder portion (15) adds the additional data accumulated in the database for addition (16) to decoded first contents in accordance with a control instruction by the relay control portion (13).

Abstract: A packet delay characteristic measuring apparatus that can accurately only measure a delay in a network even if a delay may occur also in a device that receives packets. The apparatus includes: a sending section for periodically sending out test packets each including sending time information to the network; a branching section for handing over the test packets flowing from the network to each of a plurality of communication paths by electrically branching a communication path; a plurality of receiving sections each of which is connected to the branching section for receiving the identical test packets and calculating delay times based on the sending time information; and a measurement value determining section for comparing a plurality of delay times calculated by each of the plurality of receiving sections for the identical test packets and determining the smallest delay time value as a measurement value.

Abstract: A packet capture apparatus and method including receiving packets through a network, acquiring target packets including specific information from the received packets, extracting the target packets of each session, and storing the extracted target packets, estimating a capture cycle, a capture width, and a capture start time based on static information about the target packets to determine a start time and an end time of the reception of the packets based on the capture cycle, the capture width, and the capture start time, setting the start time and the end time in control by the packet capturing part, and using the start time and the end time being set to control intermittent packet capturing, where the packets are received during each capture width every capture cycle from the capture start time.

Abstract: There is provided a measuring apparatus for acquiring packets being transmitted and received within a packet network and measuring communication quality on the basis of the acquired packets, the apparatus including a part that extracts packets acquired within one of given sampling periods, each sampling period set intermittently, and a part that measures communication quality on the basis of the packets acquired within the sampling period.

Abstract: A packet capturing apparatus and method are provided. The packet capturing apparatus includes an acquisition part acquiring a voice packet having voice information, after receiving each packet transferred in a network, from received packets. The packet capturing apparatus also includes a measuring part measuring an elapsed time after receiving the acquired voice packet and an acquisition part starting to receive a voice packet transferred in a direction opposite to a transfer direction of the acquired voice packet when the elapsed time reaches a predetermined standby time.

Abstract: A communication-quality measuring method disclosed in the present invention acquires packets to be transferred in a packet switching network and accumulates the acquired packets in an internal buffer. An acquisition amount indicating an amount of packets acquired per given unit time, a loss amount indicating an amount of packets lost during transfer in the packet switching network, and an acquisition leak amount indicating an amount of packets that cannot be accumulated in the internal buffer out of the acquired packets are measured. Based on the measured acquisition amount, loss amount, and acquisition leak amount, a packet loss rate transferred in the packet switching network and an error for the loss rate are calculated and the calculated loss rate and the loss rate error are output.

Abstract: A network fault information collecting device arranged in a packet network includes a quality degradation detecting unit which monitors packets to be regularly transmitted and received in the packet network, and detects quality degradation of the packets. The device includes a node search unit which searches for nodes on a path between transmission and reception terminals for the packet, upon detection of the quality degradation of the packets in the quality degradation detecting unit. The device includes an information collecting unit which issues an information collecting packet for each terminal searched by the node search unit, and collects and records terminal information.

Abstract: A measurement method and communication system include a writing of a creation time upon a detection packet used for detecting a communication state of a network being created into the detection packet. The method includes obtaining a send time when the detection packet was sent and sending, to a receiving apparatus which receives the detection packet, as a notification, information regarding a time period from when the detection packet was created to when the detection packet was sent. The method includes measuring, in the receiving apparatus, a delay occurring in the network based on the detection packet and the information sent as the notification.

Abstract: A packet communication quality measuring apparatus for capturing packets flowing in a packet communication network while recording capture times to measure communication quality based on the captured packets includes a detection part for detecting that a buffer in which the captured packets are stored is full and a determination part for determining a possibility of a capture failure occurring when fullness of the buffer is detected.

Abstract: Method and device for heightening communications security. Gateway 3 receives packet P1 from caller terminal 1a, and creates and transmits to receiver terminal 1b packet P2, in which destination IP address, source IP address, destination port, source port, and session ID for packet P1 are rewritten. Gateway 3 also receives packet P3 from receiver terminal 1b, and creates and transmits to caller terminal 1a packet P4, in which destination IP address, source IP address, destination port, source port, and session ID for packet P3 are rewritten. Because communications between every terminal are identifiable according to session ID, a plurality of communications through the same port may be supported which is favorable security-wise.

Abstract: A communication quality measuring apparatus comprising a connecting section establishing a connection to the packet exchange network, a capturing section capturing packets transferred over the packet exchange network, an accumulating section accumulating the packets, a control section repeating the capturing of packets in sections of fundamental processing times, a setting section setting the capturing time and the interval time within each fundamental processing time, and a determining section determining whether or not the amount of load on hardware resources of the communication-quality measuring apparatus is greater than a predetermined value.

Abstract: Method and device for heightening communications security. Gateway 3 receives packet P1 from caller terminal 1a, and creates and transmits to receiver terminal 1b packet P2, in which destination IP address, source IP address, destination port, source port, and session ID for packet P1 are rewritten. Gateway 3 also receives packet P3 from receiver terminal 1b, and creates and transmits to caller terminal 1a packet P4, in which destination IP address, source IP address, destination port, source port, and session ID for packet P3 are rewritten. Because communications between every terminal are identifiable according to session ID, a plurality of communications through the same port may be supported, which is favorable security-wise.

Abstract: A system including a unit transmitting test packets to a to-be-measured communication link at a first time interval, a unit transmitting burst loads each including a series of load packets to the communication link at a second time interval, a unit performing measurement of delay time periods in a manner that a plurality of test packets transmitted by varying elapsed time periods each from an instance of transmission of the burst load to an instance of transmission of the test packet are received from the communication link in a fluctuating time interval, a unit generating delay distributions indicative of packet occurrence frequencies in relation to a delay time period of the communication link in accordance with the measured delay time periods, a unit calculating a network load in accordance with occurrence frequencies in a specific section of the generated delay distributions.

Abstract: A communication quality measuring apparatus comprising a connecting section establishing a connection to the packet exchange network, a capturing section capturing packets transferred over the packet exchange network, an accumulating section accumulating the packets, a control section repeating the capturing of packets in sections of fundamental processing times, a setting section setting the capturing time and the interval time within each fundamental processing time, and a determining section determining whether or not the amount of load on hardware resources of the communication-quality measuring apparatus is greater than a predetermined value.

Abstract: The present invention includes a designating packet transferring step, a measurement packet transmitting step, a measurement packet transmitting step and a measurement packet collecting step. The designating packet transferring step is a step of transferring a designating packet in a target section for a communication performance measurement in the communication network, the designating packet designating a relaying apparatus which adds information to the measurement packet from among plural relaying apparatuses. The measurement packet transmitting step is a step of transmitting a measurement packet from one end of the target section. The measurement packet collecting step is a step of collecting the measurement packet transferred in the target section from among measurement packets which are transmitted in the measurement packet transmitting step.