The Research On Simulation Of Switches And Switching Networks

With the rapid development of the Internet, more and more people pay their attention to the research of network capability. As a basic element of the network, a switch plays a very important role in this research. Starting from this point, to design an interactive experimental environment or simulation tool for the research of switches and switching networks has very important significance. Based on the research on the present popular simulation tools and switched local area networks, this paper designs and develops a switch and switching network simulation system, and simulates a single switch and a three-layer switching network with this system.Firstly, this paper introduces the present situation of the development of the network simulation technology at home and abroad and the characteristics of the switch. It makes an intensive study of several popular network simulation tools. What's more, in spite of lock of detail demonstrations, an in-depth analysis of the SIM tools developed by the University of Stanford has been made through the analysis of thousands of codes.In fact, there is actually not a network stimulation tools that can stimulate every kind of networks, our research aims at a new kind of LAN environment, in which best-effort businesses and real-time traffics for control purpose are coexisted. This type system in this paper is called R/B (Real-time and Best-effort) network system. The R/B network environment is introduced and its significance is described. Through the analysis of the features of three typical kinds of LANs and the new network application demands, A stimulation tool is to be designed based on the features of R/B environment.Because the present SIM is a single switch stimulation tool, it cannot be applied to the stimulation of switch network. This paper designs and develops the network simulation system named SwitchSim through referencing the technology used in SIM and researching the characteristics of the R/B network environment, and typical load models and scheduling algorithms are designed and implemented. The fundamental theory and simulation skills of the time slot system are deeply studied. Then time slot mechanism is designed for R/B switches and switching networks. In addition, the way to produce random number in NS2 is analyzed, and the random number generator in SwitchSim tool is developed.At last, SwitchSim is used to simulate a single switch and a three-layer switching network. And the actual results prove that the designed SwitchSim has good simulating capability and satisfied effects.