Patent ID: 7738465
Filing Date: 2010-06-15
Classification: H04L

Abstract:
1. A packet forwarding device equipped with a statistics collection device for collecting statistic information for each combination of multiple pieces of information contained in a received packet header, comprising: a means for transmitting the received packet subjected to the specified processing, wherein the statistics collection device contains a first table, a second table, and a search table discrimination table for selecting either the first table or the second table based on information contained in the header, and a means for searching the first table, the second table and the search table discrimination table, the first table and the second table hold at least entries containing combinations of multiple pieces of information contained in the header, and statistic information for collection corresponding to the information, the combinations of multiple pieces of information contained in the header, and information indicating the table corresponding to that information are stored in the search table discrimination table, the first table is configured as a high speed search table for selectively skipping packet statistic information collection per flow type via sampling, and the second table is configured as a large scale search table for collecting packet statistic information for each flow type therein, when a packet is received, the search table discrimination table is searched based on a combination of multiple pieces of information contained in the header of the received packet, the statistics collection device selects either the first table or the second table according to the results of the search of the discrimination table, the selected table is searched statistic information of the received packet, and the statistic information is collected accordingly, and the first table is stored in a Content Addressable Memory (CAM) and the second table is stored in a Random Access Memory (RAM), wherein the second table is formatted in a tree structure comprised of the combinations of multiple pieces of information contained in the received packet header and corresponding statistic information.