Patent ID: 7729271

Claim:
A packet relay apparatus which receives packets, searches for the routes thereof, and transmits them to the searched routes, said packet relay apparatus comprising: a packet relay processing section to relay packets on the basis of a routing table; a packet sampling section to sample the packets which said packet relay processing section has received; a flow statistics counting section to identify each flow of the packets sampled by the packet sampling section, based on at least one of a source IP address, a destination IP address, a protocol number, a source port number and a destination port number therefor, which are included in the sampled packets; to tally, in a flow statistics table, the number of packets or bytes received per unit time for each flow on the identified flow basis therefor; and to output entries in said flow statistics table; and a flow statistics generating section to receive each said entry in said flow statistics table output from said flow statistics counting section, and to transform the tallied number of packets or bytes received per unit time in each entry into a predetermined format, wherein said flow statistics counting section extracts, from the flow statistics table, flows having a number of packets or bytes received per unit time that are less than a threshold level; accumulates the total number of the packets or bytes of all of said extracted flows; tallies the accumulated total number of the packets or bytes of all of said extracted flows as a single entry in said flow statistics table; and outputs said single entry as one of said entries output thereby.