DEVICE AND METHOD FOR MANAGING LOOKUP TABLE OF LPM-BASED CAM AND RECORDING MEDIUM THEREOF

摘要

PURPOSE: A device and a method for managing a lookup table of the LPM(Longest Prefix Matching)-based CAM(Content Addressable Memory) and a recording medium thereof are provided to arrange an upper pointer and a lower pointer in each band of data with the same prefix in length, and to prepare a space for added data by moving data only indicated by the upper pointers and the lower pointers of each data band, so as to simply update the lookup table. CONSTITUTION: A CAM(460) includes a lookup table that stores data with a long prefix starting from the lowest address. A pointer storage(420) includes a lower pointer and an upper pointer. The lower pointer memorizes an address of data with the lowest address among data with the same prefix length every band of the data with the same prefix length, and the upper pointer memorizes the next address of an address of data with the highest address among data with the same prefix length. And a table manager(440) records data of an address memorized by the lower pointer of each band in the address memorized by the upper pointer of the each band, for the each band of data with a prefix shorter than the prefix of added data if the data are added in the lookup table of the CAM(460). Also, the table manager(440) records the added data in the address memorized by the upper pointer for the band of data with the same prefix length as the added data, and updates the addresses memorized by the upper pointer and the lower pointer included in the pointer storage(420).