Comprehensive Review of SDN Controller Placement Strategies

Abstract

Software-Defined Networking (SDN) is a network paradigm introduced to overcome the inherent challenges of traditional networks. Its architecture is either deployed with a single controller or multiple controllers. While the first is not suitable for large-scale networks, the latter is confronted with a controller placement problem (CPP) in a large-scale network environment. CPP involves the challenge of deploying the optimal number of controllers within a network while meeting certain performance requirements considered conflicting in nature such as reliability, load balancing, latency, energy efficiency, and computation time. A single optimal or random placement may not be feasible in CPP and careful planning is of the essence to find an appropriate trade-off among the metrics. To achieve this, several CPP approaches have been proposed, developed, and deployed over the years, each having its unique objectives, strengths, and weaknesses. Therefore, this paper performed a comprehensive review of some of the existing approaches to identify the unique solutions offered, comprehend the different strategies and the challenges that exist as well as provide researchers with future directions aimed at improving the optimum location and allocation of controllers, in particular, for SDN application in wireless sensor network (WSN). The findings revealed several existing solutions and algorithms as well as several challenges such as the need for an efficient algorithm, attack-aware, cost-aware, and energy-aware CPP schemes while achieving a good quality of service.

Diffusion Model of Preemptive-Resume Priority Systems and Its Application to Performance Evaluation of SDN Switches

“…Investigated methodologies are divided into two groups, one looking for optimal solutions and the other for heuristic sub-optimal solutions. The problem of proper placement of controllers is also examined in [ 12 ]. The authors compare results obtained by different classes of algorithms, such as clustering, integer linear and quadratic programming, evolutionary bio-based, genetic, heuristic, greedy, and simulated annealing based on requirements such as latency, load balancing, fault tolerance, the optimal number of controllers, cost, and control plane communication.…”

SDN Wireless Controller Placement Problem-The 4G LTE-U Case

“…Previous works by the authors [14], [18] discussed related works in the wired SDN domain. Other comprehensive surveys of the CPP solutions for wired SDNs can be found in [19]- [23]. In the following, the solutions are only reviewed for the CPP for wireless SDNs, which is the topic of this research.…”

Failure Simulation in Software-Defined Networks with Differential Link Availability

“…While the problem of optimal placement of SDN controllers (CPP) has been widely studied (for some recent reviews, see [3], [7], [12]) no definitive answer is yet evident. The problem of defining what is optimal is itself complex, since many conflicting objectives may be present, usually different specializations of latency, reliability and cost [9], but which may also include less common objectives like energy-efficiency or information sharing requirements [3].…”

“…The correct placement of a suitable number of controllers is, therefore, a very important concern, and the so-called Controller Placement Problem (CPP) has been subject to a large number of studies (e.g. [3], [7]).…”