Virtual TCAM for Data Center switches

Software Defined Data Center Networks utilize a large number of rules to define routes for network flows. SDN controllers install rules at each switch in order to maximize metrics such as efficiency, delay or energy consumption. This requires each switch to store a substantial number of rules, which is not possible for current Top-of-Rack (ToR) switches as they usually have capacities of 2-4k rules. In this paper we present T-Flex (short for flexible TCAM), a technique for implementing virtual TCAM for data center switches. T-Flex can enhance the rule storage capabilities of a switch by up to 10x, and can forward incoming flows at line rate under most circumstances. Moreover, it provides full OpenFlow compatibility for use in SDN environments, and has been tested to work on a data center production grade Intel switch. Designed as an extension to virtual switches, T-Flex can provide the illusion of an unlimited TCAM in a data center switch.