Routing framework and creation algorithm in Ad Hoc based SDN

Node energy-limited and mobility,indeed,requirement of customized service,made Ad Hoc press for customization Routing.Based on the core principle of software defined networking (SDN),the control framework and the design of routing creation bran-new approach about Ad Hoc based SDN was analyzed firstly.Secondly,the hierarchical routing model was established,and the problem of routing key nodes and key link centralized selection based on service path was proposed and its algorithm was designed,which could embed customize service into physical networks via nodes mapping based network performance maximization.Finally,it corroborate the advantage of routing implement via SDN in function,performance and the whole networks utilization.Experiments show that the energy consumption of network nodes is more balanced and the overall utilization of the network is nearly 14% higher than the traditional method.     

Pluggable SDN framework for managing heterogeneous SDN networks

Software‐defined networking (SDN) is a new network paradigm that is separating the data plane and the control plane of the network, making one or more centralized controllers to supervise the behaviour of the entire network. Different types of SDN controller software exist, and research dealing with the difficulties of consistently integrating these different controller types has mostly been declared future work. In this paper, the Domino framework is proposed, a pluggable SDN framework for managing heterogeneous SDN networks. In contrast to related work, the proposed framework allows research into SDN networks controlled by different types of SDN controllers attempting to standardize the northbound API of them. Domino implements a microservice plugin architecture where users can link different SDN networks to a processing algorithm. Such an algorithm allows for, eg, adapting the flows by building a pipeline using plugins that either invoke other SDN operations or generic data processing algorithms. The Domino framework is evaluated by implementing a proof‐of‐concept implementation, which is tested on the initial requirements. It achieves the modifiability and the interoperability with an average successful exchange ratio of 99.99%. The performance requirements are met for the frequently used commands with an average response time of 0.26 seconds, and the framework can handle at least 72 plugins simultaneously depending on the available amount of RAM. The proposed framework is evaluated by means of the implementation of a shortest path routing algorithm between heterogeneous SDN networks.     

A novel multicast traffic engineering technique in SDN using TLBO algorithm

In recent years, multicast communication is widely used by network providers to deliver multimedia contents. Quality of service (QoS) provisioning is one of the most important issues while transmitting multimedia contents using multicast. Traditional IP multicasting techniques suffer from reliability, scalability and have limitations to provide appropriate QoS for multimedia applications based on service level agreement (SLA). Nowadays, the advent of software defined networking (SDN), enables network providers to manage their networks dynamically and guarantee QoS parameters for customers based on SLA. SDN provides capabilities to monitor network resources and allows to dynamically configure desired multicasting policies. In this paper, we proposed a novel multicasting technique to guarantee QoS for multimedia applications over SDN. To deliver multimedia contents in an efficient manner, our proposed method models multicast routing as a delay constraint least cost (DCLC) problem. As DCLC problem is NP-Complete, we proposed an approximation algorithm using teaching–learning-based optimization to solve this problem. We evaluated our proposed method under different topologies. Experimental results confirmed that our proposed method outperforms IP multicast routing protocol, and it achieves a gain of about 25% for peak signal-to-noise ratio.     

A virtualized infrastructure to offer network mapping functionality in SDN networks

The separation of control and forwarding planes in software‐defined networking (SDN) networks is a key issue of the SDN technology. This feature and the existence of the SDN controller allow the developing of dynamic, adaptable and manageable networks, networks that require adequate services, and applications. However, the separation of these planes prevents the use of existing powerful tools that were coded considering traditional networks. In this paper, we make use of the potential of network virtualization (NV) technologies to propose the use of a virtualized infrastructure that makes possible the incorporation of these existing services and/or applications to an SDN network, without the need for programming additional and complex software modules in the SDN controller. Thus, in this paper, NV is not employed to develop a network managed by SDN but to broaden and give support to the SDN control layer. As an example, we describe the incorporation of nmap (a versatile and powerful tool widely used by security experts for network exploration) into the SDN framework. It is only necessary to develop a simple control plane service that thanks to the proposed virtualized infrastructure allows the inclusion of this powerful management application. The result offers the complete functionality of the nmap utility to the network administrators, who control the SDN network through the out‐of‐band control plane. In addition, a northbound REST API has been defined to offer the main functionality of the tool (host discovery, port scanning, and operating system detection) to the application layer.     

SDN特征剖析及典型应用介绍

通过与基于策略的网络管控、软交换等技术的对比,梳理了SDN技术源流,阐述了SDN体系结构及其包含的网络可编程、网络虚拟化等技术思想,剖析了其创新特征和对网络发展的意义;分析了SDN目前还缺乏清晰的商业模式、集中控制器存在状态收集和可伸缩性等问题,指出违背复杂系统管控规律所带来的局限性;介绍了SDN典型应用场景,说明SDN的适用范围主要是在局部自治网络中跨IP网、光网络、无线网络等层面进行一体化管控。     

A consistent QoS routing strategy for video streaming services in SDN networks

The software‐defined networking (SDN) paradigm proposes to decouple the control plane (decision‐making process) and the data plane (packet forwarding) to overcome the limitations of traditional network infrastructures, which are known to be difficult to manage, especially at scale. Although there are previous works focusing on the problem of quality of service (QoS) routing in SDN networks, only few solutions have taken into consideration the network consistency, which reflects the adequacy between the decisions made and the decisions that should be taken. Therefore, we propose a network architecture that guarantees the consistency of the decisions to be taken in an SDN network. A consistent QoS routing strategy is then introduced in a way that avoids any quality degradation of prioritized traffic while optimizing resources usage. Thus, we proposed a traffic dispersion heuristic in order to achieve this goal. We compared our approach with several existing framework in terms of best‐effort flows average throughput, average video bitrate, and video quality of experience (QoE). The emulation results, which are performed using the Mininet environment, clearly demonstrate the effectiveness of the proposed approach that outperforms existing frameworks.     

自治系统内IP子网和SDN子网的互联机制

SDN网络与传统IP网络的互联机制是当前学术界的研究热点,但现有解决方案并不能适用于所有应用场景。为此提出了一个基于OSPF协议的IMISA架构,在一个包含 SDN 子网（基于OpenFlow）和IP子网的自治系统范围内,通过给SDN控制器添加一个OSPF路由模块,利用OSPF协议交换各自的网络信息,最终实现了2种网络的互联。     

SDN/NFV‐based handover management approach for ultradense 5G mobile networks

With the great increase of connected devices and new types of applications, mobile networks are witnessing exponential growth of traffic volume. To meet emerging requirements, it is widely agreed that the fifth‐generation mobile network will be ultradense and heterogeneous. However, the deployment of a high number of small cells in such networks poses challenges for the mobility management, including frequent, undesired, and ping‐pong handovers, not to mention issues related to increased delay and failure of the handover process. The adoption of software‐defined networking (SDN) and network function virtualization (NFV) technologies into 5G networks offers a new way to address the above‐mentioned challenges. These technologies offer tools and mechanisms to make networks flexible, programmable, and more manageable. The SDN has global network control ability so that various functions such as the handover control can be implemented in the SDN architecture to manage the handover efficiently. In this article, we propose a Software‐Defined Handover (SDHO) solution to optimize the handover in future 5G networks. In particular, we design a Software‐Defined Handover Management Engine (SDHME) to handle the handover control mechanism in 5G ultradense networks. The SDHME is defined in the application plane of the SDN architecture, executed by the control plane to orchestrate the data plane. Simulation results demonstrate that, compared with the conventional LTE handover strategy, the proposed approach significantly reduces the handover failure ratio and handover delay.     

Self-healing and SDN: bridging the gap

Achieving high programmability has become an essential aim of network research due to the ever-increasing internet traffic. Software-Defined Network (SDN) is an emerging architecture aimed to address this need. However, maintaining accurate knowledge of the network after a failure is one of the largest challenges in the SDN. Motivated by this reality, this paper focuses on the use of self-healing properties to boost the SDN robustness. This approach, unlike traditional schemes, is not based on proactively configuring multiple (and memory-intensive) backup paths in each switch or performing a reactive and time-consuming routing computation at the controller level. Instead, the control paths are quickly recovered by local switch actions and subsequently optimized by global controller knowledge. Obtained results show that the proposed approach recovers the control topology effectively in terms of time and message load over a wide range of generated networks. Consequently, scalability issues of traditional fault recovery strategies are avoided.     

Nature‐inspired meta‐heuristic algorithms for solving the load balancing problem in the software‐defined network

The growth of the networks has difficult network management. Recently, a concept called software‐defined network (SDN) has been proposed to address this issue, which makes network management more adaptable. Control and forwarding planes are separated in SDN. The control plane is a centralized logical controller that controls the network. The forwarding plane that consists of transfer devices is responsible for transmitting packets. Because the network resources are limited, optimizing the use of resources in the networks is an important issue. Load balancing improves the balanced distribution of loads across multiple resources in order to maximize the reliability and network resources efficiency. SDN controllers can create an optimal load balancing compared to traditional networks because they have a network global view. The load‐balancing problem can be solved using many different nature‐inspired meta‐heuristic techniques because it has the NP‐complete nature. Hence, for solving load balancing problem in SDN, nature‐inspired meta‐heuristic techniques are important methods. However, to the best of our knowledge, there is not a survey or systematic review on studying these matters. Accordingly, in the area of the load balancing in the SDN, this paper reviews systematically the nature‐inspired meta‐heuristic techniques. Also, this study demonstrates advantages and disadvantages regarded of the chosen nature‐inspired meta‐heuristic techniques and considers their algorithms metrics. Moreover, to apply better load balancing techniques in the future, the important challenges of these techniques have been investigated.     

An SDN approach to route massive data flows of sensor networks

With the advent of the Internet of Things (IoT), more and more devices can establish a connection with local area networks and use routing protocols to forward all information to the sink. But these devices may not have enough resources to execute a complex routing protocol or to memorize all information about the network. With proactive routing protocols, each node calculates the best path, and it needs enough resources to memorize the network topology. With reactive routing protocols, each node has to broadcast the message to learn the right path that the packets must follow. In all cases, in large networks such as IoT, this is not an appropriate mechanism. This paper presents a new software‐defined network (SDN)–based network architecture to optimize the resource consumption of each IoT object while securing the exchange of messages between the embedded devices. In this architecture, the controller is in charge of all decisions, and objects only exchange messages and forward packets among themselves. In the case of large networks, the network is organized into clusters. Our proposed network architectures are tested with 1000 things grouped in five clusters and managed by one SDN controller. The tests using OpenDayLight and IoT embedded applications have been implemented on several scenarios providing the ability and the scalability from dynamic reorganization of the end‐devices. This approach explores the network performance issues using a virtualized SDN‐clustered environment which contributes to a new model for future network architectures.     

Efficient data management and control over WSNs using SDN‐enabled aerial networks

The recent developments in collaborative search, acquisition, and tracking have hoisted the geographical barrier. The network between unmanned aerial vehicles (UAVs) and wireless sensor networks (WSNs) is one such collaboration, which comprises battery‐powered static sensor nodes that act as sources and sinks and UAVs that act as relays. This collaborative network presents with opportunities and advantages, but at the same time, configuration of such networks is an arduous task. The WSN nodes are characterized by constant depleting power. Their network itself requires constant management and reconfiguration. These requisites can be slaked through the formation of an efficient data dissemination algorithm, which acclimates according to the network state. Considering this, a data dissemination approach is presented in this paper, which constructs a virtual topology predicated on the charge of WSN nodes utilizing software‐defined networks (SDNs) through UAVs. The topology is constantly monitored and reconfigured when required. The aerial nodes are equipped with multiple‐input multiple‐output (MIMO) antennas in order to facilitate simultaneous communication with the ground nodes, the base station, and the SDN controller. An efficient sleep timer and backoff counter strategies are also utilized by the proposed approach. The SDN controller facilitates the topology formation and maintenance of a sleep timer and a backoff counter. The proposed model is compared with clustered hierarchical layouts and hexagonal cell layouts through the network simulations. The results suggest significant improvements in the proposed model for various metrics, such as lifetime, delay, latency, delivery ratio, and throughput in comparison with the existing solutions.     

基于SDN架构的地址跳变技术研究

网络嗅探作为网络攻击的前奏,对于网络安全存在较大威胁。为增强网络本身的抗嗅探窃听能力,在移动目标防御网络的地址跳变技术的研究基础上提出了一种基于传输过程的地址跳变方案,主要思想是在SDN网络架构下,控制器通过为传输路由上交换机下发不同流表来实现IP地址的跳变。仿真结果表明,可以以较小的网络开销实现跳变机制,并使网络对于网络嗅探达到较高的防御能力。     

SDI: a multi-domain SDN mechanism for fine-grained inter-domain routing

Software-defined networking (SDN) scheme decouples network control plane and data plane, which can improve the flexibility of traffic management in networks. OpenFlow is a promising implementation instance of SDN scheme and has been applied to enterprise networks and data center networks in practice. However, it has less effort to spread SDN control scheme over the Internet to conquer the ossification of inter-domain routing. In this paper, we further innovate to the SDN inter-domain routing inspired by the OpenFlow protocol. We apply SDN flow-based routing control to inter-domain routing and propose a fine-granularity inter-domain routing mechanism, named SDI (Software Defined Inter-domain routing). It enables inter-domain routing to support the flexible routing policy by matching multiple fields of IP packet header. We also propose a method to reduce redundant flow entries for inter-domain settings. And, we implement a prototype and deploy it on a multi-domain testbed.     

Migration cost optimization for service provider legacy network migration to software-defined IPv6 network

This paper studies a problem for seamless migration of legacy networks of Internet service providers to a software-defined networking (SDN)-based architecture along with the transition to the full adoption of the Internet protocol version 6 (IPv6) connectivity. Migration of currently running legacy IPv4 networks into such new approaches requires either upgrades or replacement of existing networking devices and technologies that are actively operating. The joint migration to SDN and IPv6 network is considered to be vital in terms of migration cost optimization, skilled human resource management, and other critical factors. In this work, we first present the approaches of SDN and IPv6 migration in service providers' networks. Then, we present the common concerns of IPv6 and SDN migration with joint transition strategies so that the cost associated with joint migration is minimized to lower than that of the individual migration. For the incremental adoption of software-defined IPv6 (SoDIP6) network with optimum migration cost, a greedy algorithm is proposed based on optimal path and the customer priority. Simulation and empirical analysis show that a unified transition planning to SoDIP6 network results in lower migration cost.     

Adaptive routing and wavelength assignment method based on SDN

Routing and wavelength assignment is an important resource allocation method of all-optical network.Aiming at the problem of traditional method combined with the new architecture,an adaptive multi-objective routing and wavelength assignment method based on SDN was proposed,which could realize the allocation of link resources of all-optical network through self-regulation.Based on the SDN service function chain model,service scheduling time and link service quality were taken as the scheduling objective,routing and wavelength assignment problem was constructed as the 0-1 integer programming problem,meanwhile,binary hybrid topology particle swarm optimization algorithm was used to optimize the network resources for optimal scheduling.The simulation results show that the proposed method is superior to the traditional classical algorithms in the test of recovery time,blocking rate and resource utilization.     

QL-STCT：一种SDN链路故障智能路由收敛方法

针对软件定义网络（SDN）链路故障发生时的路由收敛问题,提出了Q-Learning子拓扑收敛技术（QL-STCT）实现软件定义网络链路故障时的路由智能收敛。首先,选取网络中的部分节点作为枢纽节点,依据枢纽节点进行枢纽域的划分。然后,以枢纽域为单位构建区域特征,利用特征提出强化学习智能体探索策略来加快强化学习收敛。最后,通过强化学习构建子拓扑网络用于规划备用路径,并保证在周期窗口内备用路径的性能。实验仿真结果表明,所提方法能够有效提高链路故障网络的收敛速度与性能。     

关于SDN网络管理模式的探讨

云计算的出现给传统网络带来了巨大的挑战和改变。爆炸式的数据增长暴露了传统数据网络的不足,而这个问题催生了软件定义网络（SDN,SoftwareDefinedNetworking）。SDN把网络作为资源向上层IT业务开发,从而实现网络的动态,实时和灵活的调整,解决了私有云网络部署中的瓶颈问题。主要对现有SDN模式下的网络管理方案进行了相关探讨并对该方案提出了开放性的意见以及其不足之处。     

Multidomain Network Based on Programmable Networks: Security Architecture

This paper proposes a generic security architecture designed for a multidomain and multiservice network based on programmable networks. The multiservice network allows users of an IP network to run programmable services using programmable nodes located in the architecture of the network. The programmable nodes execute codes to process active packets, which can carry user data and control information. The multiservice network model defined here considers the more pragmatic trends in programmable networks. In this scenario, new security risks that do not appear in traditional IP networks become visible. These new risks are as a result of the execution of code in the programmable nodes and the processing of the active packets. The proposed security architecture is based on symmetric cryptography in the critical process, combined with an efficient manner of distributing the symmetric keys. Another important contribution has been to scale the security architecture to a multidomain scenario in a single and efficient way.     

层次化跨区域SDN验证示范系统的设计与建设

软件定义网络（SDN）架构给网络带来了卓越的灵活性和可管理性。为了给新型SDN技术与应用提供大规模可行性验证试验床与试点部署平台,提出了依托于CERNET的层次化跨区域SDN 异地验证示范网络试验系统的总体架构,建设了9个城市、13个节点的SDN验证示范核心网与包含3个数据中心的接入网,并对基于SDN的vCPE智能专线业务、IPv4/IPv6过渡技术、流量监控调度应用和数据中心应用进行验证与示范。