چكيده به لاتين
Software-defined networking (SDN) is a new concept in computer networks, which unlike traditional networks architecture, data and control plane are separated. The control plane includes a number of controllers responsible for monitoring, optimizing operations and management of data plane equipment. The controller usually has a limitation on the number of flows that are able to handle at any point in time. Accordingly, the number of switches the controller is also able to manage are limited. Using one controller may be enough to manage switches in a small-scale network, but in data centers and enterprise networks with increased workload and network size, the number of controllers required also increases. Using one controller in the network has advantages, but also comes with its own problems such as single-point of failure, security, QoS, scalability and load balancing. A solution to the single controller problem is to use multiple controllers, But taking advantage of a couple of controllers can increase the cost of a network and raising problems such as the number of controllers required and how to deploy them in the network as well. According to the common controller placement approach, controller placement is often limited to switches locations. Research on the location independent solution shows that the number of controllers is reduced by four times, and thus reduces network costs.
In this thesis, in the first step, by using numbers and specifications of communication equipment and controllers that we have, according to the needs of the network, which in this method, it’s based on maximum outgoing traffic from a switch, and using mathematical model we determine the minimum communication equipment and controllers with the goal of achieving a minimum cost of setting up the network. Finally, in the second step after having the equipment needed to set up the network and based on the exact coordinates of the placement location of the switches, we determine the location of controllers independent of the location of the switches. After placing the controllers we established the connections between equipment. In the end, with the calculation of the total link and the equipment, we will provide a minimum cost of setting up the network. The results of the proposed method showed that the design of the control plane with the goal of reducing costs, in addition to reducing the cost of the network, reduces the 99.9% runtime in similar situations than the previous work.
