PACKET FORWARDING DEVICE EQUIPPED WITH STATISTICS COLLECTION DEVICE AND STATISTICS COLLECTION METHOD

A packet forwarding device equipped with a statistics collection device and statistics collection method for high speed ports at a low cost while maintaining the required statistical accuracy for each flow. In order to collect a statistic flow with the required accurate statistic information this device contains a high speed flow table, a flow table made up of many flow entries, a search decision table to decide whether to search the high speed flow table or large volume flow table; and the table to be searched is decided when a packet is received. The accuracy of the statistic information for the flow requiring accurate statistic information is guaranteed by the high speed flow table. Further by setting the large volume flow table and sampling rate as needed, statistic information for many flow entries can be collected with a sufficient flow of sampled statistic information, without lowering packet forwarding performance.