Enhanced Prefix Inclusion Coding Filter-Encoding Algorithm for Packet Classification With Ternary Content Addressable Memory

Filter encoding can effectively enhance the efficiency of Ternary Content Addressable Memory (TCAM)-based packet classification. It can minimize the range expansion problem, reduce the TCAM space requirement and improve the lookup rate for IPv6. However, additional complexity will incur inevitably in the filter table update operations. Although the average update cost of the Prefix Inclusion Coding (PIC) scheme is very low, the worst-case update cost can be significantly higher. Major modifications to the PIC scheme to improve its update performance are presented. The new coding scheme is called PIC with segmented domain.