The cross-protect router: implementation tests and opportunities

The concept of flow-aware networking (FAN) has been introduced, discussed, and analyzed only with the use of mathematical models or computer simulations. This article presents the results of FAN´s first practical implementation. For the environment, the Click Modular Router was chosen. In the article, vital implementation-related issues are shown and analyzed. The results of post-implementation tests are also presented. They confirm the advantages of the XP router over the IP router. We prove that traffic in FAN is served fairly, and the packets of streaming flows are transmitted with high priority. Moreover, the test results confirm that streaming flows are served with acceptable quality even in highly loaded links, which is not observed in the classic IP network. The tests also show several problems not caught by the simulative studies available in the literature. First of all, to increase efficiency, a flow list had to be implemented in a different way than originally proposed. Also, a queuing algorithm had to be altered to eliminate too frequent changes of flow states, which resulted in a lack of stability. The presented tests ultimately prove that FAN works as a concept and that, by reaching maturity, it is ready for largescale deployment.