A rule grouping technique for weight-based TCAM coprocessors [packet classification application]

A crucial issue associated with a TCAM (ternary content addressable memory) coprocessor with weights is that no more rules can be enforced if the weights are exhausted. In this paper, the problem is identified and a rule grouping technique is proposed to solve the problem. The technique allows a virtually unlimited number of rules with arbitrary rule structures to be enforced. It requires no special hardware support and can be readily implemented in a fully programmable network processor and a weight-based TCAM coprocessor.