On centralized and distributed control of communication networks

Abstract

Networks are facing many challenges with the exponential increase in devices and traffic. The lack of seamless scalability, programmability, and remote management of traditional networks requires the investigation of new networking paradigms. Software-Defined Networking (SDN), with centralized control, promises to offer the above three features in addition to other advantages. However, legacy networking protocols have been the subject of research for a long time, to the extent that some of the techniques they use and the advantages they provide in some circumstances should not be replaced. At the same time, SDN, like any other technology, presents some shortcomings, one of which is the single point of failure. On the other hand, the centralization or distributedness of control exists beyond the area of telecommunication. Some systems, such as the nervous system or administrative and political regimes, exhibit the same interrelationship between the two types of control. These systems serve as an inspiration to designing hybrid control planes in data networks. This thesis aims to model and compare the performance of both types of control in communication network using OSPF and Openflow, identifying the strengths and weaknesses of each. It then aims to draw the control rules that govern the inter-operability of centralized and decentralized control from the comparative study and in the areas defined above, and use them to model an adaptive hybrid control system that exploits the advantages of both centralized and distributed control, with application to networks. The system is then allowed to shift either completely or partially from a centralized system to a distributed environment so as to deliver a desired performance. The model is then applied to telecommunication networks. Much work in the literature concerns operating and managing networks that contain legacy and SDN nodes. Hybrid SDN switches that support both SDN and legacy routing protocols have also been presented and studied. Our technique differs from