Research On Path Selection Mechanism In Multi-topology In OpenFlow Based On Trust Degrees

Transmission security of network information and quality of network services are facing serious challenges as Internet technologies and applications are developing rapidly. The development of network applications urgently demands to establish network services with high trust degrees. Current researches on trusted network technologies focus more on solving the trust issue of end-users and service providers in network environment. Thus, constrained by traditional network architecture, researches on trust guarantee for network transmission equipments need to be enhanced.SDN technologies based on OpenFlow have made revolutionary changes to the traditional network architecture and provided new solutions for researching and developing new network applications and improving network performance. However, deeper researches on the design of security mechanism for network equipment and the guarantee for trusted transmission of network information are required in current work on relevant technologies based on OpenFlow.Considering the above deficiencies and problems in network researches, this thesis proposes a path selection mechanism in Multi-Topology based on trust degrees to select a suitable transmission path of data flow based on the trust requirements of network information in OpenFlow.Based on trust evaluation model of network equipments, this thesis combines trust evaluation technologies and OpenFlow network, researches on the principles of OpenFlow protocol and offers a trust evaluation framework applicable to OpenFlow. This framework conducts trust evaluation both on the identity and behavior of switches in Open Flow and the links connecting these switches. Then it presents a path selection mechanism in Multi-Topology based on trust degrees. This mechanism fully considers the requirements of data flows on network trust degrees, takes the results of trust evaluation on switches and links in OpenFlow as main bases for path selection, and offers solutions when network trust degrees cannot meet the requirements of data flows, so that this mechanism could be applied to dynamic networks and data flows with different requirements on trust degrees, and effectively strengthen trust guarantee in data transmission. In this thesis, an OpenFlow network is built on Mininet platform to carry out functional testing on the path selection mechanism. Experimental results show that, compared with the selection mechanism of paths in existing controllers, the mechanism proposed in this thesis provides more sensitively and effectively the transmission path that suits the requirements of data flows on trust degrees, and at the same time effectively reduce the routing overhead of the system caused by frequent updates of trust degrees.