Abstract: An apparatus acquires a packet transmitted between a transmission-terminal and a reception-terminal, and stores the acquired packet in association with a time at which the packet has been acquired. When a first bandwidth of data packets transmitted by the transmission-terminal during a time-period from acquisition of a first ACK-packet transmitted by the reception-terminal to acquisition of a second ACK-packet transmitted by the reception-terminal subsequently to the first ACK-packet, is smaller than a second bandwidth or greater than a third bandwidth, the apparatus determines the second ACK-packet to be a packet not desired to measure a bandwidth, where the second bandwidth is calculated using an acquisition interval between first and second data packets transmitted respectively after waiting for the first and second ACK-packets, and the third bandwidth is calculated using an acquisition interval between two adjacent data packets including a data packet transmitted without waiting for an ACK-packet.

Abstract: A throughput measuring method includes: acquiring a plurality of data packets at an observation point on a network, the plurality of data packets being transmitted from a transmission source apparatus and received by a transmission destination apparatus; calculating a plurality of round trip times, for each of the data packets, from a time point of acquisition of each of the data packets transmitted from the transmission source apparatus to a time point of acquisition of response packet corresponding to each of the data packets; identifying a measurement time section including the plurality of calculated round trip times increasing in ascending order of identification numbers of the response packets; and calculating a throughput of the identified measurement time section based on data quantities of the plurality of data packets transmitted from the transmission source apparatus during the identified measurement time section.

Abstract: A method includes receiving a first packet, the first packet being including a first packet identifier and a first error detection code, storing first information indicating the first packet identifier and second information indicating the first error detection code, receiving a second packet, the second packet being including a second packet identifier and a second error detection code, comparing the second packet identifier and the second error detection code with the first information and the second information, respectively, in response to a determination that the second packet identifier corresponds to the first information and the second error detection code corresponds to the second information, discarding the second packet, in response to a determination that at least one the second packet identifier and the second error detection code does not correspond to the first information and the second information, providing the first packet and the second packet for a packet analysis.

Abstract: An operation unit detects that a received first ACK packet is an ACK packet transmitted in response to a single data packet. The operation unit determines whether to calculate a round trip time by using reception time of the first ACK packet on the basis of a window size included in the first ACK packet and a window size included in a second ACK packet acquired immediately before the first ACK packet. If the operation unit determines to calculate the round trip time, the operation unit outputs the round trip time calculated by using the reception time of the first ACK packet.

Abstract: A storage unit stores a plurality of packets collected in a wired section. An operation unit classifies the plurality of packets stored in the storage unit for each connection. The operation unit determines packets corresponding to a connection having a period in which a total data amount of packets for each of which a confirmation response packet has not arrived from a destination apparatus among packets transmitted by an information processing apparatus connected to the wired section increases when the connection is started, a round-trip time of each of the packets transmitted by the information processing apparatus not increasing monotonically in the period, to be packets of communication including the wireless section.

Abstract: In an analysis apparatus, when detecting each packet communicated via a network, an update unit updates statistical information that is stored in a continuous storage area of a storage unit and that indicates the communication state of the network for a first cycle. Then, a first processing unit reads the statistical information from the storage unit at every first cycle, and processes the statistical information and initializes the statistical information in the storage unit. A second processing unit reads partial statistical information that is part of the statistical information from the storage unit at every second cycle shorter than the first cycle, and processes the partial statistical information and initializes the partial statistical information in the storage unit.

Abstract: A packet analysis method includes acquiring a first acknowledge packet and a second acknowledge packet transmitted from the first device; acquiring a plurality of packets transmitted from the second device during a period from reception of the first acknowledge packet to reception of the second acknowledge packet; identifying a number of packets corresponds to data transmitted from the second device, by calculating a difference between a first identification number corresponding to the first acknowledge packet and a second identification number corresponding to the second acknowledge packet; calculating a plurality of bandwidth values, a number of the plurality of bandwidth values is identical to the number of packets, based on acquisition timings of the plurality of packets and an interval between the acquisition timings of two adjacent packets; and determining a bandwidth value that is to be removed from the plurality of bandwidth values by comparing the plurality of bandwidth values.