Patent ID: 7110362

Claim:
A network management system comprising: a communication network having a first edge node serving as an entrance unit to said network for a transfer signal passing through said network, a second edge node serving as an exit unit used to send out said transfer signal from said network to an outside and a relay node being mounted between said first edge node and said second edge node and on a transfer route extending from said first node to said second node; a path information acquiring unit being connected to said first edge node and second edge node so as to be communicable with said first and second edge nodes and being used to send out a tracing signal used to trace said transfer signal along said transfer route on which said transfer signal has passed, to said first edge node, and being used to acquire information about a path through which said transfer signal passes; and wherein each of said nodes is made up of a path information holding unit used to hold information about said path through which said transfer signal passes, a tracing signal residing unit used to make said tracing signal be resident when having received said tracing signal and to produce a replica of said tracing signal and a tracing signal transmitting unit used to feed said replica of said tracing signal to said nodes being adjacent to each other on said transfer route and wherein said path information acquiring unit used to acquire said information about said path on said transfer route for said transfer signal extending from said first edge node to said second edge node, from one node out of a plurality of said nodes.