Title: ScaleNet: A Platform for Scalable Network Emulation
Abstract: The need for large-scale protocol development environments for protocol testing and verification has been increasing with the rapid growth of the Internet and the evolution of network protocols. Due to approximations in network simulation, accuracy of the reproduction of protocol execution may be less than desired levels. For real networks, it is very hard to reconfigure and its behaviour is not easily reproducible. Whereas with emulation, it is easy to reconfigure and its behaviour is easily reproducible. Dummynet, netbed and remote unix lab environment(RULE) are some of the emulation platforms. Dummynet can not emulate complex network topologies. It is not implemented as a loadable kernel module. Its implementation only exists between TCP and IP layers, so it can not emulate other protocols(eg UDP). Netbed requires several resources. It uses FreeBSD jail functionality for creation of several virtual hosts. This jail functionality does not exist in other operating systems, so in that case it has to do one-to-one mapping of the virtual resources to physical resources. RULE also creates several virtual hosts on a physical machine, but routing is not possible between these virtual hosts and it is not scalable. In this work, we have created ScaleNet, an emulation platform that can emulate large networks using limited physical resources. This emulation platform can be used to test any network protocol. Several virtual hosts are created on few physical systems. NIST Net is used for applying effects such as bandwidth limitation, delay, packet duplication, packet drops etc. The approach is scalable and cost effective. We have shown that our emulation platform scales upto 50 virtual hosts per physical host, while the scalability of Netbed is restricted to about 10-20 virtual hosts per machine.