Logical Centralization Research Articles

Effect of Conflicting Flows on TCP and UDP Data Transfer Rates in OpenFlow Switch for Software-Defined Networks (SDN)

Software-defined networking (SDN) is a framework that enhances scalability and agility in network simplicity and control. It is characterized by logical centralization, improving control, and data planes. Nevertheless, additional investigation is needed to fully understand the influence of flow conflict on the transfer rate variable. The present research aims to analyze the impact of flow conflict on the efficacy of the two protocols, the transmission control protocol (TCP) and the user datagram protocol (UDP), respectively, by utilizing throughput as a measure of efficiency. The measurements are verified through SDN OpenFlow networking modeling using MININET. The findings reveal a significant average alteration in transfer rate for TCP and UDP when SDN conflict rules are present, ultimately impacting network and operational efficiency.

INVESTIGATING THE IMPACT OF TREE-BASED NETWORK TOPOLOGY ON THE SDN CONTROLLER PERFORMANCE

Software Defined Networking (SDN) is an important technology that enables a new approach to how we develop and manage networks. SDN divides the data plane and control plane and promotes logical centralization of network control so that the controller can schedule the data in the network effectively through the OpenFlow protocol. The performance and capabilities of the controller itself are important. The impact of network topology type on controller performance can be very significant. In order to have better communication in SDN, it is essential to have an analysis of the performance of specific network topologies. In this paper, we simulate ONOS and RYU controllers and compare their different network parameters under the proposed complex custom Tree-based topology. A network topology has been designed using a Mininet emulator, and the code for topology is executed in Python. From the throughput, packet transmission rate, and latency analysis, the ONOS controller displayed better results than RYU, showing that it can respond to requests more efficiently under complex SDN topologies and traffic loads. On the contrary, the RYU controller provides better results for the less complex SDN networks.

Comparison of Software Defined Networking with Traditional Networking

The Internet has caused the advent of a digital society; wherein almost everything is connected and available from any place. Thus, regardless of their extensive adoption, traditional IP networks are yet complicated and arduous to operate. Therefore, there is difficulty in configuring the network in line with the predefined procedures and responding to the load modifications and faults through network reconfiguring. The current networks are likewise vertically incorporated to make matters far more complicated: the control and data planes are bundled collectively. Software-Defined Networking (SDN) is an emerging concept which aims to change this situation by breaking vertical incorporation, promoting the logical centralization of the network control, separating the network control logic from the basic switches and routers, and enabling the network programming. The segregation of concerns identified between the policies concept of network, their implementation in hardware switching and data forwarding is essential to the flexibility required: SDN makes it less complicated and facilitates to make and introduce new concepts in networking through breaking the issue of the network control into tractable parts, simplifies the network management and facilitate the development of the network. In this paper, the SDN is reviewed; it introduces SDN, explaining its core concepts, how it varies from traditional networking, and its architecture principles. Furthermore, we presented the crucial advantages and challenges of SDN, focusing on scalability, security, flexibility, and performance. Finally, a brief conclusion of SDN is revised.

Adaptive Telemetry for Software-Defined Mobile Networks

The forthcoming set of 5G standards will bring programmability and flexibility to levels never seen before. This has required introducing changes in the architecture of mobile networks, enabling different features such as the split of control and data planes, as required to support the rapid programming of heterogeneous data planes. Software Defined Networking (SDN) has emerged as a basic toolset for operators to manage their infrastructure, as it opens up the possibility of running a multitude of intelligent and advanced applications for network optimization purposes in a centralized network controller. However, the very basic nature that makes possible this efficient management and operation in a flexible way—the logical centralization—poses important challenges due to the lack of proper monitoring tools, suited for SDN-based architectures. In order to take timely and right decisions while operating a network, centralized intelligence applications need to be fed with a continuous stream of up-to-date network statistics. However, this is not feasible with current SDN solutions due to scalability and accuracy issues. This article first analyzes the monitoring issues in current SDN solutions and then proposes a telemetry framework for software defined mobile networks capable of adapting to the various 5G services. Finally, it presents an experimental validation that shows the benefits of the proposed solution at alleviating the load on the control and data planes, improving the reactiveness to network events, and providing better accuracy for network measurements.

Optimization of depository accounting system of stock and obligation market with application of blockchain

Purpose of the study. The first goal of the study is a comparative analysis of the models of the accounting system of the stock market operating on the territory of the Russia, in particular, the model of the distributed accounting system and the model of the centralized accounting with the use of the central depository are considered. The second goal is to apply the distributed ledger technology in the development of a new model for the stock market accounting system. The goals are conditioned by the growing interest to the technology and similarity of its internal processes with the system of accounting of digital assets. The needs in optimization of the existing accounting system, bringing the system to the logical centralization are revealed. The application of distributed ledger technology for the purpose of unification of depository accounting systems is proposed. The analysis of efficiency of the given models is carried out and the criteria of efficiency estimation of each model are revealed. Materials and methods. For carrying out the research the works of description of register system genesis of stock market in Russia were applied. Works of Russian and foreign researchers in the field of influence of technology of distributed registers on accounting system and business processes of organizations are studied. The methodology for comparing models was the approach to the development of highly specialized evaluation criteria that meet the needs of the largest number of stock market participants. Results. Evaluation criteria were developed, on the basis of which the comparison of the existing models of the accounting system of stock market and the projected model on the distributed ledger technology was carried out. The needs for optimization of the existing accounting system of Russia, bring the system to the logical centralization of interaction of elements are revealed. Suggestions for the use of distributed ledger technology in order to unite the register systems of obligations have been developed The variety of elements of the accounting system of the Russian stock market was determined a large number of indicators used in comparisons of models, as well as a variety of approaches, both to the construction of the indicators themselves and to the collection of data to ensure their calculation and comparison. Conclusion. According to the results of the research it was determined that the decentralized model of the stock market accounting system on the distributed ledger technology in comparison with the classic model reduces the transaction cost of obligation right accounting operations, optimizes the complexity of the processes of interaction between the elements of the system, such as depositories and registrars, increases the transparency of the stock market, the processes of the transition of assets rights, due to which the liquidity of such assets and the increases investors interest. Decentralized model standardizes the of communication data, which has a positive effect on the indicators of information systems of participants. In comparison with the centralized model, the decentralized model eliminates the central depository transaction commission, eliminates monopolization to choose the direction of stock market depository accounting system development. Finally, the positive influence of the decentralized model on the stock market as a whole was revealed. The resulting form of relations will reduce the main cost indicators of the accounting system elements, such as transaction costs, the cost of support and development of information systems, the number of necessary formats for the application of interaction with counterparties.

ANCHOR

Software-defined networking (SDN) decouples the control and data planes of traditional networks, logically centralizing the functional properties of the network in the SDN controller. While this centralization brought advantages such as a faster pace of innovation, it also disrupted some of the natural defenses of traditional architectures against different threats. The literature on SDN has mostly been concerned with the functional side, despite some specific works concerning non-functional properties such as security or dependability. Though addressing the latter in an ad-hoc, piecemeal way may work, it will most likely lead to efficiency and effectiveness problems. We claim that the enforcement of non-functional properties as a pillar of SDN robustness calls for a systemic approach. We further advocate, for its materialization, the reiteration of the successful formula behind SDN: ‘logical centralization’. As a general concept, we propose anchor , a subsystem architecture that promotes the logical centralization of non-functional properties. To show the effectiveness of the concept, we focus on security in this article: we identify the current security gaps in SDNs and we populate the architecture middleware with the appropriate security mechanisms in a global and consistent manner. Essential security mechanisms provided by anchor include reliable entropy and resilient pseudo-random generators, and protocols for secure registration and association of SDN devices. We claim and justify in the article that centralizing such mechanisms is key for their effectiveness by allowing us to define and enforce global policies for those properties; reduce the complexity of controllers and forwarding devices; ensure higher levels of robustness for critical services; foster interoperability of the non-functional property enforcement mechanisms; and promote the security and resilience of the architecture itself. We discuss design and implementation aspects, and we prove and evaluate our algorithms and mechanisms, including the formalisation of the main protocols and the verification of their core security properties using the T amarin prover.

Guest Editorial Scalability Issues and Solutions for Software Defined Networks

Software Defined Networking (in short SDN, which is also an acronym for Software Defined Network), has emerged as a response to the limitations and complexities of traditional network architectures. At the heart of SDN lies the idea to consolidate the control over network devices into a logically centralized (software) controller separated from the data plane. The separation of the control plane and the data plane is realized via an open programming interface between the data plane switches and the SDN controller. The decoupling allows the control plane to evolve independently of the data plane, which enables faster innovation since software often exceeds hardware in innovation speed. Furthermore, logical centralization has the potential to simplify network operation and management by providing a single focal point where the consequences of management actions can be assessed, and possibly rejected if they would lead to some violation of operational constraints. OpenFlow, the standard SDN protocol today, is based on a simple match-action paradigm which results in great flexibilities, e.g., in terms of traffic engineering, definition of flows, as well as in-band network control functionalities.

Risk based Security Enforcement in Software Defined Network

Software Defined Network (SDN) paradigm provides intelligent and efficient management of different network control functions (NF) depending on changes in traffic behavior, service providers’ requirements and application context. However, the logical centralization of controllers’ functions opens up challenges towards enforcing security perimeter over the underlying network and the assets involved. In this paper, we propose a risk assessment model for pro-active secure flow control and routing of traffic in SDN. The proposed model determines threat value of different SDN entities by analyzing vulnerability and exposure with respect to Common Vulnerability Scoring System (CVSS). The risk of a given traffic is calculated as cumulative threat values of the SDN entities that guides the flow and routing control functions in generating secure flow rules for the forwarding switches. The efficacy of the proposed model is demonstrated through extensive case studies of an enterprise network.

Software-Defined Next-Generation Satellite Networks: Architecture, Challenges, and Solutions

Traditional satellite networks depend on the closed and planned architecture. Thus, there are many challenges such as configuration update, new communication and networking technologies introduction, truly-differentiated services provision, satellite network device interoperability, and the integration of satellite and terrestrial networks. Software-defined networking (SDN) has the features of flexibility, programmability, and logical centralization, which increases network resource utilization, simplifies network management, reduces operating cost, and promotes the evolution and innovation. In this paper, a new software-defined architecture for next-generation satellite networks, called SoftSpace, is presented. The concepts of network function virtualization, network virtualization, and software-defined radio are exploited in the SoftSpace to facilitate the incorporation of new applications, services, and satellite communication technologies. This can not only reduce the capital expenditures and operational expenditures but also integrate satellite networks with terrestrial networks seamlessly, as well as can improve the interoperability of satellite network devices. In addition, we discuss the challenges and solutions for network management. The necessary network management instruments including multi-layer controller architecture, cooperative traffic classification, and utility-optimal network virtualization are presented. Finally, we discuss the challenges and solutions for space networking. The software-defined space networking solutions including quality of experience-aware space routing, SDN-enabled hybrid fault recovery mechanism, and software-defined space mobility management are developed.

A Multi-Pronged Approach to Adaptive and Context Aware Content Dissemination in VANETs

Content dissemination in Vehicular Ad-hoc Networks (VANETs) has the potential to enable a myriad of applications, ranging from advertising, traffic and emergency warnings to infotainment. This variety in applications and services calls for mechanisms able to optimize content storing, retrieval and forwarding among vehicles, without jeopardizing network resources. Content Centric Networking (CCN), takes advantage of inherent content redundancy in the network in order to decrease the utilization of network resources, improve response time and content availability, coping efficiently with some of the effects of mobility. Floating Content (FC), on the other hand, holds potential to implement efficiently a large amount of vehicular applications thanks to its property of geographic content replication, while Software Defined Networking (SDN), is an attractive solution for the lack of flexibility and dynamic programmability that characterizes current VANET architectures. By implementing a logical centralization of the network, SDN enables dynamic and efficient management of network resources. In this paper, for a few reference scenarios, we illustrate how approaches that combine CCN, FC and SDN enable an innovative adaptive VANET architecture able to efficiently accommodate to intermittent connectivity, fluctuating node density and mobility patterns on one side and application performance and network resources on the other side, aiming to achieve high QoS. For each scenario, we highlight the main open research challenges, and we describe possible solutions to improve content dissemination and reduce replication without affecting content availability.

CentFlow: Centrality-Based Flow Balancing and Traffic Distribution for Higher Network Utilization

Next-generation networks (NGNs) are embracing two key principles of software defined networking (SDN) paradigm functional segregation of control and forwarding plane, and logical centralization of the control plane. A centralized control enhances the network management significantly by regulating the traffic distribution dynamically and effectively. An eagle-eye view of the entire topology opens up the opportunity for an SDN controller to refine the routing. Optimizing the network utilization in terms of throughput is majorly dependent on the routing decisions. Open Shortest Path First (OSPF) and Intermediate System to Intermediate System (IS-IS) are well-known traditional link state routing protocols proven with operation over operator networks for a long time. However, these classical protocols deployed distributively fall short of expectation in addressing the current routing issues due to the lack of a holistic view of the network topology and situation, whereas handling enormous traffic and user quality of experience (QoE) requirements are getting critical. IP routing in NGN is widely expected to be supported by SDN to enhance the network utilization in terms of throughput. We propose a novel routing algorithm–CentFlow, for an SDN domain to boost up the network utilization. The proposed weight functions in CentFlow achieve smart traffic distribution by detecting highly utilized nodes depending on the centrality measures and the temporal node degree that changes based on node utilization. Furthermore, the frequently selected edges are penalized thereby augmenting the flow balancing and dispersion. CentFlow reaps greater benefits on an SDN controller than the classical OSPF due to its comprehensive view of the network. Experimental results show that CentFlow enhances the utilization of up to 62% of nodes and 49% of links, respectively, compared to an existing Dijkstra algorithm-based routing scheme in SDN. Furthermore, nearly 6.5% more flows are processed networkwide.

Toward Secure Software Defined Vehicular Networks: Taxonomy, Requirements, and Open Issues

The emerging software defined vehicular networking (SDVN) paradigm promises to dramatically simplify network management and enable innovation through network programmability. Despite noticeable advances of SDNs in wired networks, it is also becoming an indispensable component that potentially provides flexible and well managed next-generation wireless networks, gaining massive attention from both industry and academia. In spite of all the hype surrounding emerging SDVNs, exploiting its full potential is demanding, and security is still the key concern and an equally arresting challenge. On the contrary, the complete transformation of the network into an SDN structure is still questionable, and the security and dependability of SDNs have largely been neglected topics. Moreover, the logical centralization of network intelligence and the tremendously evolving landscape of digital threats and cyber attacks that predominantly target emerging SDVNs will have even more devastating effects than they are in simple networks. Besides, the deployment of the SDVNs' novel entities and several architectural components drive new security threats and vulnerabilities. Since the SDVNs architectural layers and their corresponding APIs are heavily dependent on each other, this article aims to present a systematic top-down approach to tackle the potential security vulnerabilities, attacks, and challenges pertaining to each layer. The article contributes by presenting the security implications of the emerging SDVNs to devise comprehensive thematic core layered taxonomies together with external communication APIs. Moreover, we also describe the potential requirements and key enablers toward secure SDVNs. Finally, a plethora of open security research issues are presented that may be deemed appropriate for young researchers and professionals around the globe to tackle in anticipation of secure SDVNs.

A Survey of Securing Networks Using Software Defined Networking

Software Defined Networking (SDN) is rapidly emerging as a new paradigm for managing and controlling the operation of networks ranging from the data center to the core, enterprise, and home. The logical centralization of network intelligence presents exciting challenges and opportunities to enhance security in such networks, including new ways to prevent, detect, and react to threats, as well as innovative security services and applications that are built upon SDN capabilities. In this paper, we undertake a comprehensive survey of recent works that apply SDN to security, and identify promising future directions that can be addressed by such research.

Elastic network functions: opportunities and challenges

Network function virtualization (NFV) and software defined networking (SDN) are key technology enablers for cost reductions and new business models in networking. The possibility to automatically and dynamically scale network services at run time is one of the main claims of NFV. Elastic NFV could be similar to what elastic cloud services provide for compute, with pay-per-use cost models for customers. However, control of resources for elastic services is far from trivial. We show how current NFV and SDN architectures could support elastic resource services for network functions (NFs). We reveal that the current NFV architecture does not allow recursive resource orchestration, therefore preventing resource scaling requests from being handled by a resource orchestrator overseeing the entire domain where an NF is executed. We introduce a logical centralization of joint compute and network resource orchestration as a UNIFY framework, which enables direct control of elastic resources for the NFs. We show opportunities and challenges associated with such an architecture.

Intent: an integrated environment for distributed heterogeneous databases

Intent: an integrated environment for distributed heterogeneous databases