Modeling Network Behaviour By Full-System Simulation

Due to the network technology advances, an order-of-magnitude jump has been produced in the network bandwidth. This fact has returned to wake up the interest on protocol offloading, since network communication is a key factor for system performance. Thus, much research work on offloading is been done, particularly on TCP offloading as it has been the main transport protocol for many years, and in fact, it is the most used protocol in the networks. Nevertheless, some recent studies on protocol offloading have produced some controversy about its benefits. This paper describes a model to simulate the protocol offloading by using the simulator Simics. It can be used for a functional system simulation, including the application program, the operating system, the protocol stack and the device drivers, since network-oriented applications require this kind of full-system simulation. Nevertheless, as Simics does not provide a detailed network I/O model, in this paper we describe the way we have overcome this problem.