Research On Key Technology Of Network Emulation With High Performance

The platform of network emulation and evaluation is becoming the critical infrastructure in networking technology verification and network security assessments,and the basis of the platform is the construction of virtual target networks using digital emulation,virtualization as well as physical test bed.The contradiction between emulation fidelity and emulation efficiency is the pivotal problem in virtual target network construction,that is to say,network emulation should solve the problems of how to advance the scale of emulation topology and network flow simultaneously while ensuring fidelity.Facing the problem,the methods are divided into two categories: On one hand,for digital emulation and other single virtual target network-construction technology,researches should focus on performance improvement;On the other hand,researches should also assemble advantages of digital emulation,virtualization and physical test bed in fidelity and scale,so as to realize the organic integration of different network construction technologies.Facing the contradiction between emulation fidelity and emulation efficiency,in this paper,the network emulation technology with high performance is studied from two aspects:on one hand,with the assistance of digital emulation technology,the methods to improve emulation efficiency and ensure emulation fidelity are found;On the other hand,the high-efficiency method for integrating the advantages digital emulation and physical test bed is studied.Specifically,the main contents of this paper include the following 3 aspects:1)For the construction technology of virtual target network,domestic and international research status are studied,analyzed and summarized.The principles and classifications of network emulation are introduced,Furthermore,the generation process of emulation topology and the emulation tools are analyzed and studied,finally the characteristics of the emulation tools are analyzed and compared.All the analysis and researches provide a solid theoretical basis for the purpose and verification about the proposed method.2)Based on the focusing topology,a new method with high performance is presented.The main idea of this method is to divide the virtual target network topology into two areas:FTA(Focusing Topology Area)and NFTA(Non-Focusing Topology Area).In FTA area,the discrete event emulation technique is used to ensure fidelity,and in NFTA Area,the Co-Abstraction method of Queue parameters and Network packets are used to reduce the calculating cost.Compared with traditional methods,the complex network emulation experiment based on NS2 shows the method can reduce the computational cost by 89%,and the emulation performance of speed is nearly 10 times higher,and the average error rate of the emulation is only 2~4%.In conclusion,the new method has a better performance than other methods not only in reducing the computational cost,also in guaranteeing simulation fidelity in FTA.3)In this part,a flexible emulation method to access arbitrarily virtual and physical networks is presented.With this method,digital emulation and physical test bed can achieve a well seamless integration,digital emulation can improve the emulation scale effectively,and physical test bed can provide emulation fidelity effectively.By constructing the fusion ofvirtual and physical virtual networks emulation system,the architecture,key technologies and functions implementation are analyzed and studied,then the realization of the interactive communication between networks is emphasized,finally the flexible and configurable accessing of physical network to digital emulation network are discussed.The experiment results show the proposed method have better flexibility in constructing network topology under the circumstances of virtual and real fusion platform is connected normally.