Software Defined Networking Virtualization Research Articles

Software-Defined Virtual Private Network for SD-WAN

Software-Defined Wide Area Networks (SD-WANs) are an emerging Software-Defined Network (SDN) technology to reinvent Wide Area Networks (WANs) for ubiquitous network interconnections in cloud computing, edge computing, and the Internet of Everything. The state-of-the-art overlay-based SD-WANs are simply conjunctions of Virtual Private Network (VPN) and SDN architecture to leverage the controllability and programmability of SDN, which are only applicable for specific platforms and do not comply with the extensibility of SDN. This paper motivates us to refactor traditional VPNs with SDN architecture by proposing an overlay-based SD-WAN solution named Software-Defined Virtual Private Network (SD-VPN). An SDN-based auto-constructed VPN model and its evaluating metrics are put forward to automatically construct overlay WANs by node placement and service orchestration of SD-VPN. Therefore, a joint placement algorithm of VPN nodes and algorithms for overlay WAN service loading and offloading are proposed for SD-VPN controllers. Finally, a three-layer SD-VPN system is implemented and deployed in actual network environments. Simulation experiments and system tests are conducted to prove the high-efficiency controllability, real-time programmability, and auto-constructed deployability of the proposed SD-VPN. Performance trade-off between SD-VPN control channels and data channels is evaluated, and SD-VPN controllers are proven to be extensible for other VPN protocols and advanced services.

Software-Defined Virtual Private Network for SD-WAN

Software-Defined Wide Area Networks (SD-WANs) are an emerging Software-Defined Network (SDN) technology to reinvent Wide Area Networks (WANs) for ubiquitous network interconnections in cloud computing, edge computing, and the Internet of Everything. The state-of-the-art overlay-based SD-WANs are simply conjunctions of Virtual Private Network (VPN) and SDN architecture to leverage the controllability and programmability of SDN, which are only applicable for specific platforms and do not comply with the extensibility of SDN. This paper motivates us to refactor traditional VPNs with SDN architecture by proposing an overlay-based SD-WAN solution named Software-Defined Virtual Private Network (SD-VPN). An SDN-based auto-constructed VPN model and its evaluating metrics are put forward to automatically construct overlay WANs by node placement and service orchestration of SD-VPN. Therefore, a joint placement algorithm of VPN nodes and algorithms for overlay WAN service loading and offloading are proposed for SD-VPN controllers. Finally, a three-layer SD-VPN system is implemented and deployed in actual network environments. Simulation experiments and system tests are conducted to prove the high-efficiency controllability, real-time programmability, and auto-constructed deployability of the proposed SD-VPN. Performance trade-off between SD-VPN control channels and data channels is evaluated, and SD-VPN controllers are proven to be extensible for other VPN protocols and advanced services.

A Short Review on the Dynamic Slice Management in Software-Defined Network Virtualization

Software-Defined Network (SDN) is a contemporary networking technology that offers enhanced network flexibility and streamlines network management processes. Virtual Software-Defined Networking (vSDN) enables the dynamic allocation and sharing of physical networking resources among several slices, each representing distinct service providers or services. Each tenant is granted autonomous control over their respective services or applications within the Virtual Network (VN). Network virtualization allows providers to deliver novel, advanced services while enhancing efficiency and dependability. Utilizing numerous virtual networks on a specific infrastructure presents difficulties in implementing effective resource allocation mechanisms to prevent congestion and resource scarcity while maintaining the Service Level Agreements (SLAs) in the vSDN. A limited body of research has focused on dynamic slice allocation in the vSDN domain. This article will briefly review dynamic resource management, focusing on slice resource dynamic allocation through SDN hypervisors. The survey outlined that very few studies have tackled the impact of dynamicity slice management in vSDN, and there are research gaps in implementing proactive and intelligent frameworks for slice management in vSDN.

AgentVisor: Agent-Based Network Hypervisor for Autonomic Network Virtualization

A network hypervisor is a novel solution for network virtualization that allows the dynamic creation of virtual networks to facilitate independent business solutions to numerous tenants over a shared network infrastructure. This article proposes an agent-based network hypervisor (AgentVisor) architecture that virtualizes controller agents, separated from tenants' controllers to support high levels of adaptation, automation and autonomy of virtual software-defined networking networks (vSDNs). The controller agents enable closed control loop automation of systematic data collection, data-driven decision-making and autonomic control actions for monitoring, configuration and fault handling of vSDNs without intervention of tenants' controllers in a cloud/edge environment. The controller agent also offers an extended northbound interface with tenants' controllers to support policy and intelligence management based on artificial intelligence and machine learning algorithms. Through controller agent virtualization, the proposed AgentVisor architecture enables a multiagent system of autonomic vSDNs that facilitate independent business solutions for different markets over a shared infrastructure for fifth generation (5G) vision and beyond.

ENHANCEMENT OF TRAFFIC LOAD BALANCING IN SOFTWARE DEFINED NETWORK

software defined network (SDN) and virtualization network function (NFV) are cooperatively perceived as the most encouraging bearing for adaptable programmability of organization control capabilities and conventions with dynamic use of organization assets. SDN gives the deliberation of organization assets over obvious application programming interface to accomplish fundamental topology independent numerous inhabitant networks with required Quos and service level agreement (SLAs). NFV worldview sends network capabilities as programming occasions, specifically, VNFs on item equipment utilizing virtualization procedures. Along these lines, virtual IP capabilities, for example, load adjusting, steering, and sending or firewall, can work as VNF in a cloud with a positive result in network execution. In this paper, we meant to accomplish traffic load adjusting by utilizing a virtual SDN (SDN) regulator as NFV. With SON, when there is lopsided and expanded load, optional SDN regulators can be added to share this heap. The need of optional not entirely settled and a duplicate SON with the very same setups as unique SON is made, which works precisely and shares traffic load offsetting errands with a unique SON regulator. Both SON regulators are autonomously put in the cloud with straight forwardness guaranteeing that each client in the organization knows all about the presence of the recently made auxiliary SON regulator. We tentatively approved the heap adjusting in Fat-Tree geography involving two SDN regulators in a Mininet emulator. The outcomes showed half improvement in normal burden, 41% improvement in normal deferral, and significant enhancements concerning ping reaction, data transmission use, and throughput of the framework .

Resilient Control Plane Design for Virtual Software Defined Networks

Control plane survivability in virtual software-defined networks (vSDN) – where multiple tenants share the same physical infrastructure – is even more critical than in normal SDN networks. A reliable communication channel from the switches through the network hypervisor to the virtual controller is inevitable in order to avoid state inconsistencies, tenant isolation and security issues on the virtual switches. Although reliable controller placement and control plane design was thoroughly investigated in SDNs, there was a lack of attention for resilient hypervisor placement and control path design for vSDNs. Therefore, in this paper we make a two-fold contribution towards a survivable vSDN control plane. First, we propose an approximation algorithm for (hypervisor) placement which – in contrast with traditional approaches which minimize the average latency to the hypervisors as an objective function – focuses on finding the appropriate number of hypervisor instances to satisfy the control path length constraints declared in the service level agreements, leaving enough options open for self-driving network designs and intelligent algorithms. Second, we propose a general dynamic program that calculates minimum length paths traversing specific type of nodes in a given order, and apply it to find control paths from the virtual controller of the slice to the virtual switches traversing the corresponding hypervisor location. We conduct thorough simulations on real-world topologies to demonstrate the effectiveness of our approaches in no failure and single link failure scenarios.

Virtual SDN Network Embedding Algorithm Based on Load Balance

Aiming at Software Defined Network (SDN) virtualization environment, a virtual SDN (vSDN) network embedding method based on fruit fly algorithm is proposed to minimize the overall load imbalance and average control delay of the network. The simulation indicates that the proposed method improves the vSDN request acceptance rate. Besides, it has good load balance performance of the underlying physical SDN network, and reduces the communication delay for controller-to-switch.

Alleviating Heterogeneity in SDN-IoT Networks to Maintain QoS and Enhance Security

Software-defined networks (SDNs) offer unique and attractive solutions to solve challenging management issues in Internet of Things (IoT)-based large-scale multitechnological networks. SDN-IoT network collaboration is innovative and attractive but expected to be extremely heterogeneous in future generation IoT systems. For example, multitechnology network, network externality, and nodes heterogeneity in SDN-IoT may seriously affect the flow or application-specific quality-of-service (QoS) requirements. Furthermore, it highly influences security adoption in a network of interconnected IoT nodes. We observe that both QoS and security are interdependent and nonnegligible factors, thus we emphasize that in order to alleviate heterogeneity it is inevitable to study both these factors hand to hand (or vice versa ). With this aim, first, we discuss significant and reasonable cases to encourage researchers to study QoS and security integrally in order to alleviate heterogeneity at SDN-IoT control plane. Second, we propose a framework which successfully transforms the $m$ heterogeneous controllers to $n$ homogeneous controller groups. The key metric of our observation and analysis is the SDN controller’s response time. Following this, to validate our approach, we use the mathematical model and a proof of concept (PoC) in a virtual SDN ecosystem is demonstrated. From performance evaluation, we observe that the proposed framework significantly alleviates heterogeneity which helps to maintain QoS and enhance security. This fundamental analysis will enable network security individuals to deal heterogeneity, QoS, and security, of SDN-IoT, in more successful and promising ways.

SDN-based server clusters with dynamic load balancing and performance improvement

Software-defined networking (SDN) is a state-of-the-art architectural approach to network management that allows more flexible management of a complicated large-scale network. For providing services with high performance, availability, and scalability, server clustering is widely used. This study develops a server cluster based on OpenFlow, which is the most common SDN protocol. To utilize cluster resources effectively, this study focuses on the server-side load-balancing issue and increases the performance for a cluster of servers with different processing capabilities. We have proposed a novel load balancing algorithm, named dynamic weighted random selection (DWRS). DWRS considers the real-time server loads when dispatching requests to servers. Underutilized servers are assigned higher weights, so they have a higher possibility of being selected to process requests. To increase system performance, we modify the flow of packet handling in the Floodlight controller. A multi-threaded technique is used to effectively utilize the parallel processing capability of multiple cores, which speeds up the processing of packet-in messages when selecting the target server. This prevents the controller from becoming overloaded, especially when a large number of packet-in messages arrive. To demonstrate effectiveness and feasibility, we deploy our experimental environment using real hardware, instead of using Mininet to set up a virtual SDN testbed. Experimental results show that the proposed DWRS with multi-threaded implementation outperforms other policies, especially in a heterogeneous environment.

Multi-domain virtual network embedding with dynamic flow migration in software-defined networks

Software Defined Networking (SDN) decouples the control and data planes of a network, and employs a central controller to provide effective use of network resources and ease of service provision. Virtualization in SDN empowers the virtual SDN networks to share common physical network infrastructures, and, thus, make them capable for versatile service provisioning. In such setting, SDN hypervisor supports multiple virtual SDN network (vSDN) in which each vSDN has its own controller. To create virtual networks and achieving optimal sharing of physical network resources, virtual network embedding (VNE) algorithms are designed. Single domain VNE is a well-studied problem in NV literature. However, in most of the real life scenarios, VNs are provisioned across heterogeneous administrative domains belonging to different Infrastructure Providers (InPs).In this paper, we propose a VNE algorithm, namely vSDN-CLA, using Irregular Cellular Learning Automata (ICLA) for multi-domain SDN networks. We consider two aspects – optimal mapping of virtual nodes and links into multi-domain substrate network, and optimal placement of SDN controller with respect to throughput and end-to-end delay. We extend the vSDN-CLA by considering dynamic flow migration to achieve resource optimal routing. We evaluate the proposed schemes using Mininet. We observe that the proposed schemes outperform the existing benchmark schemes with respect to throughput, end-to-end delay, and virtual network request acceptance ratio under both the single and multi-domain environments.

Traffic Load Balancing Using Software Defined Networking (SDN) Controller as Virtualized Network Function

SDN and NFV are collaboratively recognized as the most promising bearing for flexible programmability of network control functions and protocols with dynamic usage of network resources. SDN provides the abstraction of network resources over well-defined APIs to achieve underlying topology-independent multiple tenant networks with required QoS and SLAs. NFV paradigm deploys network functions as software instances, namely, VNFs on commodity hardware using virtualization techniques. In this way, virtual IP functions, such as load balancing, routing, and forwarding or firewall, can operate as VNF in a cloud with a positive outcome in network performance. In this paper, we aimed to achieve traffic load balancing by using a virtual SDN (vSDN) controller as a VNF. With vSDN, when there is uneven and increased load, secondary vSDN controllers can be added to share this load. The need of secondary vSDN is determined and a copy vSDN with exactly the same configurations as original vSDN is created, which operates accurately and shares traffic load balancing tasks with an original vSDN controller. Both vSDN controllers are independently placed in the cloud with transparency assuring that every client in the network is familiar with the existence of the newly created secondary vSDN controller. We experimentally validated the load balancing in Fat-Tree topology using two vSDN controllers in a Mininet emulator. The results showed 50% improvement in average load, 41% improvement in average delay, and considerable improvements in terms of ping response, bandwidth utilization, and throughput of the system.

DROpS: A demand response optimization scheme in SDN-enabled smart energy ecosystem

With an exponential increase in the utilization of intellective appliances, meeting the energy demand of consumers by traditional power grids is a significant challenge. In integration, the amalgamation of electric vehicles, industrial Internet-of-Things (IoT), and smart communities with power grids has escalated the global energy demand. Consequently, the desideratum for a reliable energy supply and resilient energy ecosystem has incentivized the evolution of Smart Grids (SG). Such intelligent grids are equipped with autonomous controllers and advanced technologies like advanced metering infrastructure, smart sensors, and accounting management software. However, the existing demand response management and energy supply techniques are lagging behind in meeting the desired objectives in the SG ecosystem. In order to handle these challenges, a Demand Replication Optimization Scheme (DROpS) for the smart energy ecosystem is designed in this paper. In addition, a Multi-Leader Multi-Follower Stackelberg game is formulated in this paper to operate with the proposed scheme. However, the success of DROpS depends heavily on real-time communication between the consumers and the suppliers. Hence, dynamic and scalable network architecture is required to handle the seamless data generated by a sizably voluminous number of connected sensors, devices, and smart appliances deployed in the SG. For the successful operation of the architecture, a Software-Defined Networking (SDN)-enabled control scheme for flow management is additionally developed. In the proposed scheme, the SG ecosystem is divided into multiple zones such that the dedicated virtual SDN controllers are deployed for network resource utilization in an optimized manner. The proposed scheme is evaluated using a real smart home test bed and data traces from the Haryana power grid. The effectiveness of the proposed scheme is demonstrated in terms of significant gains observed for load variation and latency.

A virtual cluster embedding approach by coordinating virtual network and software-defined network

Virtual cluster, as a fundamental service of cloud computing, is an important delivery model of cloud services. Allocating physical resources for a virtual cluster is known as virtual cluster embedding (VCE), which has a significant impact on the performance. VCE includes the components of virtual machine, virtual switch, virtual link, virtual software-defined network (SDN) controller and cluster system controller. VCE needs to be considered comprehensively to adapt the influencing factor weight proportion and to be flexible for different types of embedding. This paper, based on the topology of the cloud data center network, develops a coordinated VCE approach, called CoVCE. The approach combines virtual network with SDN to form virtual SDN and weakens slightly the constraints of VM placement. The network centrality, correlation property and resource fragmentation are optimized with multiple objectives to receive more requests, increase the throughput and decrease network delay and runtime. The CoVCE method integrates not only the logical topology of virtual machines in the cluster but also the relationship with virtual switch, virtual link and control services. This does not only optimize the placement location of virtual components, but also allows the virtual resources to migrate upon virtual cluster requests. The method further improves the utilization of physical resources and reduces resource fragmentation. According to extensive simulation and emulation experiments and comparison with correlative algorithms, CoVCE effectively reduces network delays, offers a higher embedding efficiency, improves user experiences and, to some extent, also improves the revenue/cost ratio and throughput.

Towards full virtualization of SDN infrastructure

With the emerging multi-tenant virtual networks in the cloud data center and the network slicing in wide-area network, full virtualization of the hardware network infrastructure is required. In this work, we propose SVirt, a full virtualization architecture of the software defined networking (SDN) infrastructure, which can flexibly support multiple virtual networks (tenants) to simultaneously run SDN on top of the same physical network. In order to simultaneously run multiple virtual SDN switches with different processing logics on the same physical switch, we redesign the physical switch’s processing pipeline with a “late-binding key extractor (LBX)”. In the control plane, SVirt enables “many-to-one” and “one-to-many” mapping when allocating the physical resource for a virtual network, which embraces arbitrary topology and ternary content-addressable memory (TCAM) resource demanded by a virtual network. In the data plane, SVirt explicitly carries the forwarding context information in the packets, overcoming the “context-loss problem” in a virtual network. We develop a NetFPGA prototype of SVirt switch. Event-driven simulations and prototype-based experiments demonstrate that, compared with traditional approaches, SVirt significantly enhances the cloud’s capability to accept various virtual SDN requests with resource utilization ratio of more than 90% and improves the network’s throughput by around 236%. Besides, SVirt can hold more flows than traditional approaches, thus reducing two-order more table misses.

TNGuard: Securing IoT Oriented Tenant Networks Based on SDN

In the paradigm of infrastructure-as-a-service cloud computing involving an Internet of Things network, customers outsource their infrastructure to the cloud. An outsourced infrastructure is a virtual infrastructure that mimics the physical infrastructure of the precloud era; it is therefore referred to as a tenant network (TN) in this paper. This practice draws upon the notion of TN abstraction , which specifies how TNs should be managed. However, current virtual software-defined network (SDN) technology uses an SDN hypervisor to attain TNs, where the cloud administrator is given much-more-than-necessary privileges; thus, not only could violation of the security principle of least privilege occur, but the threat of a malicious or innocent-but-compromised administrator may be present. Motivated by this need, we propose the specification of TN abstraction, including its functions and security requirements. Then, we present a platform-independent concretization of this abstraction called TNGuard , which is an SDN-based architecture that protects the TNs while removing unnecessary privileges from the cloud administrator. In order to show that TNGuard concretizes the TN abstraction, we present an instantiation of TNGuard on the Xen virtualization platform with the Ryu controller. Experimental results show that the resulting system is practical, incurring a small performance overhead.

Realizing Highly-Available, Scalable, and Protocol-Independent vSDN Slicing With a Distributed Network Hypervisor System

In this paper, we design and implement a distributed network virtualization hypervisor (NVH) system, namely, DPVisor, which can provide superior network programmability based on protocol-oblivious forwarding to realize highly-available, scalable, and protocol-independent virtual software-defined network slicing. The experimental comparisons indicate that DPVisor achieves comparable performance as ONVisor ( i.e. , an OpenFlow-based ONOS benchmark), in terms of the message processing latency, message processing throughput, and failure recovery time. Moreover, to optimize the performance of the distributed NVH systems, we carefully adjust the consistency model used in the state synchronization of NVH instances and propose a local cache-based scheme to balance the tradeoff between the consistency and availability of network status. Our experimental results confirm that the message processing throughput of the distributed NVH systems can be greatly improved ( i.e. , for both DPVisor and ONVisor), while the data consistency among NVH instances is still maintained well.

Minimizing Flow Statistics Collection Cost Using Wildcard-Based Requests in SDNs

In a software-defined network (SDN), the control plane needs to frequently collect flow statistics measured at the data plane switches for different applications, such as traffic engineering, QoS routing, and attack detection. However, existing solutions for flow statistics collection may result in large bandwidth cost in the control channel and long processing delay on switches, which significantly interfere with the basic functions, such as packet forwarding and route update. To address this challenge, we propose a cost-optimized flow statistics collection (CO-FSC) scheme and a cost-optimized partial flow statistics collection (CO-PFSC) scheme using wildcard-based requests, and prove that both the CO-FSC and CO-PFSC problems are NP-hard. For CO-FSC, we present a rounding-based algorithm with an approximation factor $f$ , where $f$ is the maximum number of switches visited by each flow. For CO-PFSC, we present an approximation algorithm based on randomized rounding for collecting statistics information of a part of flows in a network. Some practical issues are discussed to enhance our algorithms, for example, the applicability of our algorithms. Moreover, we extend CO-FSC to achieve the control link cost optimization FSC problem, and also design an algorithm with an approximation factor $f$ for this problem. We implement our designed flow statistics collection algorithms on the open virtual switch-based SDN platform. The testing and extensive simulation results show that the proposed algorithms can reduce the bandwidth overhead by over 39% and switch processing delay by over 45% compared with the existing solutions.

SR-PVX: A Source Routing Based Network Virtualization Hypervisor to Enable POF-FIS Programmability in vSDNs

We design and implement a novel network virtualization hypervisor (NVH), which leverages source routing (SR) and provides network programmability based on the protocol-oblivious forwarding flow instruction set (POF-FIS), to realize protocol-independent virtual software-defined networks (vSDNs). The NVH, namely SR-PVX, uses a novel SR-based mechanism to ensure that the substrate switches can process packets from vSDNs with very small flow-table consumption. We design the network architecture, packet format, and packet processing procedure, and implement them to experimentally demonstrate that SR-PVX can control substrate POF switches to accomplish the SR-based vSDN slicing. We also perform an experiment to show that the POF-enabled vSDN created by SR-PVX can easily realize a stateful firewall with its POF-FIS programmability.

Software-defined network virtualization: an architectural framework for integrating SDN and NFV for service provisioning in future networks

SDN and NFV are two significant innovations in networking. The evolution of both SDN and NFV has shown strong synergy between these two paradigms. Recent research efforts have been made toward combining SDN and NFV to fully exploit the advantages of both technologies. However, integrating SDN and NFV is challenging due to the variety of intertwined network elements involved and the complex interaction among them. In this article, we attempt to tackle this challenging problem by presenting an architectural framework called SDNV. This framework offers a clear holistic vision of integrating key principles of both SDN and NFV into unified network architecture, and provides guidelines for synthesizing research efforts toward combining SDN and NFV in future networks. Based on this framework, we also discuss key technical challenges to realizing SDN-NFV integration and identify some important topics for future research, with a hope to arouse the research community's interest in this emerging area.

Control Plane Latency With SDN Network Hypervisors: The Cost of Virtualization

Software defined networking (SDN) network hypervisors provide the functionalities needed for virtualizing software-defined networks. Hypervisors sit logically between the multiple virtual SDN networks (vSDNs), which reside on the underlying physical SDN network infrastructure, and the corresponding tenant (vSDN) controllers. Different SDN network hypervisor architectures have mainly been explored through proof-of-concept implementations. We fundamentally advance SDN network hypervisor research by conducting a model-based analysis of SDN hypervisor architectures. Specifically, we introduce mixed integer programming formulations for four different SDN network hypervisor architectures. Our model formulations can also optimize the placement of multi-controller switches in virtualized OpenFlow-enabled SDN networks. We employ our models to quantitatively examine the optimal placement of the hypervisor instances. We compare the control plane latencies of the different SDN hypervisor architectures and quantify the cost of virtualization, i.e., the latency overhead due to virtualizing SDN networks via hypervisors. For generalization, we quantify how the hypervisor architectures behave for different network topologies. Our model formulations and the insights drawn from our evaluations inform network operators about the trade-offs of the different hypervisor architectures and help choosing an architecture according to operator demands.