Content Addressable Memory
Liu Gang, Zhang Deyun,Li Shenglei,Gao Lei
(School of Electronics and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China)
Abstract:To solve the problem of routing look up and storing in high performance routers, a method is proposed by using pruning algorithm and extendable mask technique to compress routing table. The algorithm searches for equivalent routing items and deletes redundant ones. The routing items with same next hop and same prefix length are merged as many as possible by the extendable mask technique which taking advantage of the characteristic of discontinuous mask based on ternary content addressable memory (TCAM). The increment update algorithm which uses the logic minimization ideas and prefix extension is utilized to carry out the remerge in the process of dynamical update of the routing table. Experiments indicate that the number of routing items can be reduced more than 40%.
Keywords:routing table;ternary content addressable memory;discontinuous mask