Support Multiple Auxiliary TCP/UDP Connections in SDN Simulations Based on ns-3

As software-defined networking (SDN) grows beyond its original aim to simply separate the control and data network planes, it becomes useful both financially and analytically to provide adequate mechanisms for simulating this new paradigm. A number of simulation/emulation tools for modeling SDN, such as Mininet and ns-3, are already available. However, none of them supports multiple auxiliary connections in SDN simulation/emulation, which is one of the key features added in OpenFlow 1.3. In this paper, we extended the existing OFSWITCH13 framework to support multiple auxiliary connections in SDN simulations based on ns-3. This work allows multiple TCP/UDP connections to be built between a switch and a controller in the simulation. Furthermore, we performed case studies to investigate the impact of auxiliary connections on SDN performance, which is valuable for designing a scalable SDN network.