FLOW COMMUNICATION QUALITY ESTIMATION METHOD, FLOW COMMUNICATION QUALITY ESTIMATION DEVICE, AND FLOW COMMUNICATION QUALITY ESTIMATION PROGRAM

摘要

PROBLEM TO BE SOLVED: To estimate communication quality online with performing neither active measurement nor state management of all the packet captures and flows on a network.;SOLUTION: Once a first packet flowing from a node A toward a node B is detected, a flow key i is read out to find K hash values, counter values Ci at corresponding bit map positions are added up by one, and time at positions corresponding to the K hash values on a time table is set to current time Tnow. Once a second packet flowing from B toward A is detected, a reverse rotation key is generated so as to find K hash values on input of the reverse rotation key, and when the counter values Ci corresponding to the K hash values all satisfy Ci≥1, the counter values at K places are decreased by one, time at the K places is read out to extract the oldest time T_oldi, so that a value Tnow-T_oldi obtained by subtracting the oldest time T_oldi from the current time Tnow is estimated as a reciprocal propagation delay time RTTi.;COPYRIGHT: (C)2013,JPO&INPIT