Using TCAM efficiently for IP route lookup
Yan Sun, Haiqin Liu, Min‐Sik Kim · 2011
Ternary Content Addressable Memories (CAMs) are widely used by high-speed routers to find matching routes in a routing table, because they enable the longest prefix matching operation to complete in a single clock cycle. However, they are costly and their power consumption is very high and some solutions have been proposed. But some issues have not been well studied: first, the memory accesses often take down the high speed of TCAMs; second, the prefixes must be sorted in prefix length decreasing order, which makes the update of routing table very slow. Third, even though the TCAMs are pretty fast, they can only process one match at one time, which make them unscalable. In this paper, we first discuss these problems and propose an efficient algorithm to solve these problems.