a new approach in fault tolerance in control level of sdn

Nowadays, the world of communication and information has undergone many changes, the rapidly growing trend of computer systems in terms of computing and storage and retrieval methods on the one hand and on the other hand a slow or almost constant trend in computer networks and non-response to the current needs of companies, organizations, telecommunication service providers as well as network designers face a series of limitations such as complexity, lack of scalability and lack of coordination between market needs and network capabilities and the introduction of cloud services and virtual servers. network designers have taken a big step forward in the development of networks, and the solution to achieve this progress in networks is the use of software-based networks. in recent years, despite much research in the field of this type of network, there is still a need for optimizations in this area. one of the challenges that currently needs work and development is the issue of fault tolerance and failure in these networks. in this paper, various failure tolerance methods in software-defined networks are introduced.