Patent ID: 7120125
Filing Date: 2006-10-10
Classification: H04L

Abstract:
1. Communication performance measuring equipment measuring communication performance of a communication system in which at least one client and at least one server are connected via a network including a plurality of routers, in which the communication performance measuring equipment is communicable with a client subject to evaluation, included in said at least one client, and a server subject to evaluation, included in said at least one server, the communication being through a path branching from a path in a branching node which exists on the path between said client and said server subject to evaluation, the communication performance measuring equipment comprising: a communicating unit communicating via the network according to TCP/IP; an input unit receiving a parameter which includes at least a server identifier identifying said server subject to evaluation and a client identifier identifying said client subject to evaluation or an access point to be used by said client and represents a communication environment to be evaluated; a communication controlling unit controlling communication operation of said communicating unit according to a predetermined procedure, the communication operation being performed for acquiring a predetermined file from a server; a packet transmitting/receiving unit transmitting/receiving a predetermined control packet to/from a destination identified by an identifier which is specified according to an inputted transmission instruction; a situation inspecting unit collecting information about transmitting/receiving conditions of said predetermined control packet transmitted to each destination and of a predetermined control packet returning from each destination in response to the transmitted control packet; a primary transmission instructing unit inputting, to said packet sending/receiving unit, a transmission instruction to specify the client identifier and an identifier identifying a branching node as destinations, according to receiving conditions of a data packet or a control packet in said communicating unit; a delay estimating unit estimating a difference between a delay time in transmitting a data packet from said server subject to evaluation to said client subject to evaluation, based on a predetermined delay model and said information collected by the situation inspecting unit in a course of exchanging said predetermined control packet with the client subject to evaluation and with the branching node, and a delay time in the data packet reaching said communication performance measuring equipment from the server subject to evaluation; a reply controlling unit emulating an acknowledgement from said client subject to evaluation, by adjusting a time instant at which said communicating unit is to transmit an acknowledge packet upon receiving a data packet or a control packet from the server subject to evaluation, according to the estimated difference delay times; and a performance estimating unit collecting information about progress in the communication with said subject to evaluation by said communicating unit, and estimating communication performance on a communication path between the client and the server based on the collected information.