A comprehensive survey of load balancing techniques in software-defined network

Software defined networking (SDN) is an emerging network paradigm that decouples the control plane from the data plane. The data plane is composed of forwarding elements called switches and the control plane is composed of controllers. SDN is gaining popularity from industry and academics due to its advantages such as centralized, flexible, and programmable network management. The increasing number of traffics due to the proliferation of the Internet of Thing (IoT) devices may result in two problems: (1) increased processing load of the controller, and (2) insufficient space in the switches’ flow table to accommodate the flow entries. These problems may cause undesired network behavior and unstable network performance, especially in large-scale networks. Many solutions have been proposed to improve the management of the flow table, reducing controller processing load, and mitigating security threats and vulnerabilities on the controllers and switches. This paper provides comprehensive surveys of existing schemes to ensure SDN meets the quality of service (QoS) demands of various applications and cloud services. Finally, potential future research directions are identified and discussed such as management of flow table using machine learning.

Software Defined Networking Flow Table Management of OpenFlow Switches Performance and Security Challenges: A Survey

Deployment of new optimized routing rules on routers are challenging, owing to the tight coupling of the data and control planes and a lack of global topological information. Due to the distributed nature of the traditional classical internet protocol networks, the routing rules and policies are disseminated in a decentralized manner, which causes looping issues during link failure. Software-defined networking (SDN) provides programmability to the network from a central point. Consequently, the nodes or data plane devices in SDN only forward packets and the complexity of the control plane is handed over to the controller. Therefore, the controller installs the rules and policies from a central location. Due to the central control, link failure identification and restoration becomes pliable because the controller has information about the global network topology. Similarly, new optimized rules for link recovery can be deployed from the central point. Herein, we review several schemes for link failure recovery by leveraging SDN while delineating the cons of traditional networking. We also investigate the open research questions posed due to the SDN architecture. This paper also analyzes the proactive and reactive schemes in SDN using the OpenDayLight controller and Mininet, with the simulation of application scenarios from the tactical and data center networks.

Software-Defined Networking Approaches for Link Failure Recovery: A Survey

The centralized architecture in software-defined network (SDN) provides a global view of the underlying network, paving the way for enormous research in the area of SDN traffic engineering (SDN TE). This research focuses on the load balancing aspects of SDN TE, given that the existing reactive methods for data-plane load balancing eventually result in packet loss and proactive schemes for data plane load balancing do not address congestion propagation. In the proposed work, the SDN controller periodically monitors flow level statistics and utilization on each link in the network and over-utilized links that cause network congestion and packet loss are identified as bottleneck links. For load balancing the identified largest flow and further traffic through these bottleneck links are rerouted through the lightly-loaded alternate path. The proposed scheme models a Bayesian Network using the observed port utilization and residual bandwidth to decide whether the newly computed alternate path can handle the new flow load before flow admission which in turn reduces congestion propagation. The simulation results show that when the network traffic increases the proposed method efficiently re-routes the flows and balance the network load which substantially improves the network efficiency and the quality of service (QoS) parameters.

A Proactive Flow Admission and Re-Routing Scheme for Load Balancing and Mitigation of Congestion Propagation in SDN Data Plane

Nowadays, traditional networks are suffering from lack of information, easy management, and hard QoS guarantee. Recently, SDNs overcome these limitations. They provide network agility, programmability, and centralized network control. These features facilitate solving many of the security, performance, management and QoS issues. In this paper, we propose an SDN framework that leverages programmability and centralized control to provide a level of QoS. Knowing the state of the whole network helps optimizing the decision towards enhancing the network efficiency. The presented framework basically contains modules that provide monitoring, route determination, rule preparation, and configuration functionalities. The monitoring module analyzes ports utilization and probs the links delay. The route determination module relies on the shortest path algorithm, with or without QoS guarantee. Two QoS parameters, namely, port utilization and delay are considered in the monitoring and the route determination. The proposed framework is tested in a fat-tree topology with an OpenDayLight (ODL) controller. Experiments are conducted to prove the efficiency of the presented framework over the traditional standalone controller with the built-in features. Results showed that using the presented framework, with or without QoS reduces the overall average delay by 57%, jitter by 25% and packet loss by 67%. Moreover, the monitored port utilization was reduced by 30% on average.

A QoS Framework for SDN-Based Networks

The growing power demand in day-to-day life paves way for more renewable energy-based resources in our life. Wind energy is one other most reliable energy in India and is expeditiously increasing in the recent years. Amidst the various wind turbines available for wind power extraction, the Permanent Magnet Synchronous Generator (PMSG) has many advantages owing to its attractive concept. The past research on this machine have analysed the various techniques used for extracting utmost power from the available wind energy. This review paper analyses the best control techniques that are available for controlling the PMSG, Maximum power point tracking (MPPT) methods both stereotyped as well as smart techniques and charging control techniques in both balanced along with unbalanced load conditions for a standalone PMSG based Wind Energy Conversion System (WECS). 

PMSG based WECS: Control techniques, MPPT methods and control strategies for standalone battery integrated system

Software Defined Networking (SDN) is a new approach in network architecture which decouples the control plane from data plane. The SDN controller has the global view of the underlying network, enabling enormous research works in the area of traffic engineering (TE). Existing congestion control solutions for SDN TE are either reactive or proactive in nature. In reactive schemes when congestion event occurs the source is informed which then reacts by rate adjustment and in proactive scheme pre computation of protection path demands additional resources. We propose a proactive flow monitoring method to reduce congestion and packet loss in SDN. This technique reduces packet loss by automatically re-routing congested link's traffic through a dynamically computed alternate path. Simulation result shows that proposed scheme reduces average packet loss leading to overall increase in network efficiency.

Flow monitoring scheme for reducing congestion and packet loss in software defined networks

The centralized architecture in software-defined network (SDN) provides a global view of the underlying
network, paving the way for enormous research in the area of SDN traffic engineering (SDN TE). This research focuses on the load balancing aspects of SDN TE, given that the existing reactive methods for data-plane load balancing eventually result in packet loss and proactive schemes for data plane load balancing do not address congestion propagation. In the proposed work, the SDN controller periodically monitors flow level statistics and utilization on each link in the network and over-utilized links that cause
network congestion and packet loss are identified as bottleneck links. For load balancing the identified largest flow and further traffic through these bottleneck links are rerouted through the lightly-loaded alternate path. The proposed scheme models a Bayesian Network using the observed port utilization and residual bandwidth to decide whether the newly computed alternate path can handle the new flow load before flow admission which in turn reduces congestion propagation. The simulation results show that
when the network traffic increases the proposed method efficiently re-routes the flows and balance the network load which substantially improves the network efficiency and the quality of service (QoS) parameters.

Maintaining the nominal frequency value in each and every area of the power system becomes a major challenge to the power system engineers. Along with this, the variation of the power in tie line (PTie) is also a major problem. The main objective of the Load Frequency Control (LFC) is to diminish the transient deviancy in the area frequency and the tie line power and make the steady state error almost zero. A review is made on the Ant Colony Optimization (ACO) and Firefly Algorithm (FA) based LFC controllers. The review will give a better clarity for the new researchers to select the controller for LFC. The performance of the ACO ad FA is compared and the inference is made that system response depends not only on the optimization algorithm but also on the type of controller used. 

K Ranjitha

Papers

PMSG based WECS: Control techniques, MPPT methods and control strategies for standalone battery integrated system

A Proactive Flow Admission and Re-Routing Scheme for Load Balancing and Mitigation of Congestion Propagation in SDN Data Plane

Flow monitoring scheme for reducing congestion and packet loss in software defined networks

A Proactive Flow Admission and Re-Routing Scheme for Load Balancing and Mitigation of Congestion Propagation in SDN Data Plane

Load frequency controller based on ant colony and firefly algorithm optimization - A review