The significant impact of information and communication technology (ICT) on Greenhouse Gas emissions has caused a considerable research interest in energy management of network devices in recent years. As the amount of power consumption in routers and switches is a function of their working frequency, one approach to energy saving is to adapt working frequency of such devices dynamically and proportional to their traffic load. This paper describes this approach in Software Defined Networking (SDN) framework by proposing a Mixed Integer Linear Programming (MILP) formulation for a network of FPGA based interconnected Openflow switches. The prerequisite information of switch power profile is obtained by running experimental tests. The proposed method is applied to an infrastructural dataset extracted from the standard SNDlib database. Simulation results show that frequency scaling technique reduces power consumption by more than 37% in comparison to other well-known power-saving approaches.

The current architecture of data center networks is a combination of Ethernet switches and routers. However, this architecture cannot satisfy the requirements of these networks. Ethernet switches are flexible, have simple configuration, but are not scalable. Routers provide better scalability and efficient use of bandwidth, but are costly. This architecture has a noticeable overhead configuration and maintenance. So, if we had a larger Layer 2 networks, number of routers and consequently the costs will be lessened. Many methods are presented for this purpose.In this paper introduce some main requirement center data networking and characteristic of proposed methods. Among of these methods, Openflow is preferred.But the control overhead of Openflow is high. One way to reduce the control overhead by separating big and small flows and letting the controller to control only the big flows. ECMP routing is a method that can be used for routing small flows. However Openflow does not support ECMP. In this paper, a new method based on Openflow is proposed to replace ECMP. The proposed method can achieve performance comparable to ECMP.

By separating the data layer from the control layer in the software defined network and the possibility of centralized and programmable management, many limitations and common problems in traditional networks can be solved or improved. One of the existing problems in these networks is the issue of congestion and its control. In software defined networks, the use of information under the supervision of domain controllers and the collection of network statistics can be useful in controlling or preventing congestion. When an SDN switch node is subjected to many requests, the network becomes congested, and to solve this problem, the controller can use network virtualization and switch migration, taking into account the free resources available in the switches and links.  In this paper, a software-based network approach for congestion control and optimal resource management called VNR_CCP is presented. In this approach, an attempt has been made to control congestion by calculating the nodes and links profit to search for congestion and request the virtual network to reduce the existing load and manage resources. The result of the simulation using the NS2 simulator shows that the proposed approach has better performance compared to the similar method. It was concluded that the throughput has increased by 4.3%, the delay has decreased by 5.3%, and the average cost has decreased by 26% compared to the similar method..

Flood attacks are among the most devastating distributed denial of service (DDoS) attacks. In these attacks, attackers try to use up resources by sending massive floods of packets in order to seriously challenge the provision of services. Hierarchical architecture and numerous weaknesses in the structure of communication protocols in conventional networks lead to the fact that firewalls cannot provide an integrated and effective mechanism against these attacks. With the emergence of Software Defined networking (SDN), there are new prospects for solving structural and security problems in Traditional networks. In this paper, a heterogeneous method proposed based on cooperation between traditional service provider and software-based controller (SDN) to deal with flooding attacks. In this method, the attack detection module is located in servers and the call module is located in controller(SDN). In order to simulate the heterogeneous method the MiniNet emulator is used in combination with the Pox controller. Next, the simulated model is evaluated and it is finally concluded that besides protecting against attacks in conventional networks, the proposed method provides other benefits including the extent of computational load and the response time compared to other Software Defined methods.

Software-defined network (SDN) is the next generation of network architecture thatby separating the data plane and the control plane enables centralized control with the aim of improving network management and compatibility. However, due to the centralized control policy, this type of network is prone to Inaccessibility of control plane against a denial of service (DoS) attack. In the reactive mode, a significant increase in events due to the entry of new flows into the network puts a lot of pressure on the control plane. Also, the presence of recurring events such as the collection of statistical information from the network, which severely interferes with the basic functionality of the control plane, can greatly affect the efficiency of the control plane. To resist attack and prevent network paralysis, this paper introduces a new architecture called SAHAR, which consists of a control box consisting of a coordinator controller, a primary flow setup controller, and one or more (as needed) secondary flow setup controller(s). Assigning monitoring and managing tasks to the coordinator controller reduces the load of flow setup controllers. In addition, dividing the incoming traffic between the flow setup controllers by the coordinator controller distributes the load at the control plane. Thus, by assigning the traffic load resulting from a denial-of-service attack to one or more secondary flow setup controller(s), the SAHAR architecture can prevent the primary flow setup controller from impairment and resist DoS attacks. Tests show that SAHAR performs better in the face of a DoS attack than existing solutions.

In recent years, Software Defined Networks (SDN) have been raised as a promising approach to improve the network programmability and management of computer networks. It consists in separating the control plane from the data plane and centralizing the control part of the network. Due to the rapid growth of computer networks in terms of number of switches and the amount of transiting traffic, the distributed architecture with centralized view on the network has been designed for control plane, enhancing the scalability, availability, fault tolerance and reliability. In such a distributed architecture, the load balancing between controllers plays an important role towards the optimal use of networking resources. To address the aforementioned challenges, we propose a stable distributed solution for load balancing between controllers in software defined networks. The proposed solution collects information on the amount of load of controllers and their corresponding switches. Based on this knowledge, the controller with the highest overload migrates the switch leading to the best enhancement in load balancing of the network to the least-loaded controller, if the network load is not balanced and the migration benefit is significant compared to its cost. The proposed solution inhibits simultaneous migrations triggered by distributed controllers to avoid cascade re-migrations and ensures the network stability. The results of the test-bed study of the proposed approach show that out solution outperforms other counterparts up to 15% in terms of average memory consumption, 50% in terms of controller traffic throughput and 70% in terms of processing time of the overloaded controllers.

The rise of Software-Defined Networking (SDN) has revolutionized network management, offering greater flexibility and programmability. However, ensuring the accuracy of packet forwarding remains paramount for maintaining network reliability and security in SDN environments. Unlike traditional IP networks, SDN separates the control plane from the data plane, creating new challenges for securing data transmission. Existing verification methods designed for IP networks often cannot be directly applied to SDN due to this architectural difference. To address the limitations of existing verification methods in SDN networks, new approaches are necessary. This research proposes a novel parallel method for verifying packet forwarding, building upon concepts from DYNAPFV. The proposed approach aims to overcome specific limitations of existing methods (including DYNAPFV), such as scalability issues, slow verification times. Simulations demonstrate significant improvements compared to DYNAPFV. The proposed parallel method achieves a 92% reduction in time required to identify malicious nodes within the network. The results also reveal a trade-off between security and verification time. As the probability of packet integrity confirmation increases from 0. 8 to 0. 99, system security strengthens, but the time to detect malicious switches also increases.

Software-Defined Networking (SDN) is a viable approach for management of large and extensive networks with flexible quality of service requirements and huge data traffic. Due to the central role of SDN controllers in traffic engineering and performance of software-defined networks on one hand, and diversity of available SDN controllers on the other hand, an evaluation framework is required to study and compare the architectural choices and performance of distributed and centralized SDN controllers in action. In this paper, we propose a comprehensive framework for performance evaluation of Openflow SDN controllers. In this simulation platform, we analyze both centralized and decentralized architectures for controller deployment. Performance of controllers is evaluated based on Quality of Service (QoS) measures including delay and throughput in different network topologies under different workloads. The impact of routing protocols on controller performance in data center networks is also analyzed. Our results can provide valuable insights for scalable design and proper deployment of SDN controllers in the real world scenarios.

Software-Defined Network (SDN) introduces centralized network control via the Openflow protocol, enhancing network management, traffic routing, and security policy enforcement. However, SDN's centralized nature also introduces vulnerabilities, particularly to cyberattacks targeting the controller and communication channels. This study presents a resilience assessment methodology for SDN under cyberattack conditions, leveraging Markov process theory to model system states and transitions. Three SDN architectures were evaluated under various attack scenarios, revealing that traditional configurations lack sufficient resilience against synchronous attacks and controller breaches. To address these vulnerabilities, we propose an enhanced SDN protection framework integrating controller redundancy, automatic reconfiguration mechanisms, and anomaly detection using Long Short-Term Memory (LSTM) networks. The methodology was validated through simulations in the EVE-NG environment, demonstrating improved SDN stability under cyber threats. These findings provide a foundation for designing more resilient SDN infrastructures, ensuring network continuity and security against evolving cyber threats.