Patent ID: 9654364
Date: 2017-05-16
CPC Classifications: H04L,H04W

Claim:
1. A bandwidth measuring device which communicates, via a public network, with a server which distributes a packet set by changing a window size of a congestion window, the packet set being constituted by packets, the number of which is equivalent to the window size, comprising: a RTT obtaining unit, executed by a microprocessor, to obtain a measurement value of a round-trip time in a communication channel used for communication between the bandwidth measuring device and the server; a loss ratio obtaining unit, executed by the microprocessor, to obtain a measurement value of a packet loss ratio in the communication channel; a receiving unit comprising a communication port that receives the packet set distributed from the server; a returning unit comprising a communication port that returns, when the packet set distributed from the server is received, an acknowledgement response packet corresponding to each of packets included in the packet set to the server; a first determining unit, executed by the microprocessor, to determine whether or not a retransmission timeout occurrence condition for determining whether or not a retransmission timeout is occurring is satisfied; and a calculating unit, executed by the microprocessor, to calculates an estimate value of a bandwidth in the communication channel, on the basis of a determination result of the first determining unit, wherein: where the estimate value of the bandwidth is represented by BW, the measurement value obtained by the RTT obtaining unit is represented by RTT, the measurement value obtained by the loss ratio obtaining unit is represented by p, the timeout time is represented by T, and the data size is represented by MSS.