Emunet "Emulator of Network Systems" a General Framework

Abstract

The project discussed here provides a general tool, the architecture of which allows to emulate various network configurations, and to implement various synchronization algorithms for distributed control, distributed data or functions. This emulation enables the measurement of various characteristics of these algorithms: resiliency, overhead, fairness, response time and so on. This tool resides in a physically local network, built with homogeneous microcomputers. The desired network is simulated on this physical network. The topology of the physical network supporting the simulation is a star. The central node is considered from the other satellite computers as a simple transport medium which emulates the links of the required network to which each one is connected. In the central node a simple interpreter performs the desired emulated network (loop, multidrop, mesh.....) by consulting a description of the links of this network. The simulation is made, using 3 layers of software in the central node emulator:first level: connections with the various computers of the physical network and data link control protocols, second level : path control where the routing of the various messages is performed between the satellites in the simulation. third level : traffic supervision, keeping track of the different transactions and to develop measurements and statistics on the running of the simulated network.In the satellites, the distributed systems and applications are implemented. This tool is intended to facilitate the implementation and the testing of algorithms for distributed control as well as algorithms for distributed data: ticketing algorithms, virtual rings, logical clocks or any other. Even more, it is designed to measure the different characteristics of these algorithms so as to permit their comparison. Its modularity authorizes also to perform the simulation of various faults in the satellites.