Traffic Modeling Of Internet And Application Research In Network Simulation

Network simulation is a new auxiliary planning and designing technology developed in recent years, first at all this technology can rapidly and effectively build a topology model and expediently modify the model, then the network performance parameters can be gotten by network simulation to provide reliable data for network planning and designing. Secondly the network simulation can verify or compare different design schemes and tell us which scheme is better according to performance result of simulation, as a result the investment risk can be reduced and the reasonableness of the scientific decision-making can be increased in the network construction.The traffic characteristic of network largely affects the performance of the whole network. The main research contents of this paper are how to build an exact and real traffic model. Traffic modeling includes background traffic modeling and application traffic modeling. The background traffic is an end-to-end traffic based on IP layer collected from the real network. .The performance parameters of IP lower layers can be obtained by simulation based on background traffic. Application traffic is a traffic based on the application layer, through which the performance parameters of TCP layer and application layer can be gotten. In general a complete traffic model should consist of die application traffic model and the background traffic model, all the performance parameters of the whole network are available if the complete traffic models are integrated.In this paper, firstly we introduce some basic concepts and application processions are analyzed in detail about the network simulation technology, then the works are introduce about traffic analysis and traffic modeling in the world, the main research contents of this paper are presented in the end of Chapter 1.The methods of traffic are discussed in Chapter 2 and a new hybrid simulation method is put forward based on a lot of simulation experiments. This method combines the advantages of the application traffic modeling and the background traffic modeling, and improves the efficiency of network simulation.The process of the background traffic modeling is described in Chapter 3 in detail, and solves admirably the technology problem about the interface of traffic data and OPNET software. At the same time, the APT background traffic simulation model is put forward by analyzing and comparing three traffic models.In Chapter 4, the mathematical models of the application layer traffic are set up byanalyzing their performance parameters, which is a new idea about application modeling. The traffic planning problem has been analyzed and simulated based on the components of the real network traffic and the effective bandwidths.In Chapter 5, the PDFs of the client request packet size, of the client request time, and of the server response packet size, and the sever response time can be obtained by analyzing the traffic data collected based on TCP layer. Many PDF files are merged, analyzed, transacted and their corresponding PDF mathematical models are set up, simultaneously the application of the PDF is researched in network performance analysis. This research is an original work about application traffic modeling.In chapter 6, an example is given about how to apply traffic modeling to netwo?model of 163/169 backbone network in Guang Zbou B of Guang Dong telecommunication network..A summary is given and a direction of research in the future is presented in Chapter 7The functions of the traffic analysis tool CSPA developed by myself are introduced in the appendix.