Performances of the Data Vortex switch architecture under nonuniform and bursty traffic

The Data Vortex switch architecture has been proposed as a scalable low-latency interconnection fabric for optical packet switches. This self-routed hierarchical architecture employs synchronous timing and distributed traffic-control signaling to eliminate optical buffering and to reduce the required routing logic, greatly facilitating a photonic implementation. In previous work, we have shown the efficient scalability of the architecture under uniform and random traffic conditions while maintaining high throughput and low-latency performance. This paper reports on the performance of the Data Vortex architecture under nonuniform and bursty traffic conditions. The results show that the switch architecture performs well under modest nonuniform traffic, but an excessive degree of nonuniformity will severely limit the scalability. As long as a modest degree of asymmetry between the number of input and output ports is provided, the Data Vortex switch is shown to handle very bursty traffic with little performance degradation.     

A policy based framework for quality of service management in software defined networks

Growth in multimedia traffic over the Internet increases congestion in the network architecture. Software-Defined Networking (SDN) is a novel paradigm that solves the congestion problem and allows the network to be dynamic, intelligent, and it centrally controls the network devices. SDN has many advantages in comparison to traditional networks, such as separation of forwarding and control plane from devices, global centralized control, management of network traffic. We design a policy-based framework to enhance the Quality of Service (QoS) of multimedia traffic flows in a potential SDN environment. We phrase a max-flow-min-cost routing problem to determine the routing paths and presented a heuristic method to route the traffic flows in the network in polynomial time. The framework monitors the QoS parameters of traffic flows and identifies policy violations due to link congestion in the network. The introduced approach dynamically implements policy rules to SDN switches upon detection of policy violations and reroutes the traffic flows. The results illustrate that the framework achieves a reduction in end-to-end delay, average jitter, and QoS violated flows by 24%, 37%, and 25%, respectively, as compared to the Delay Minimization method. Furthermore, the proposed approach has achieved better results when compared to SDN without policy-based framework and reduced end-to-end delay, average jitter, and QoS violated flows by 51%, 62%, and 28%, respectively.

     

DraLCD:一种新的数据中心流量工程方法

流量均衡是为了避免网络拥塞而作为流量工程中的路由优化目标提出来的,由于数据中心网络的流量特性,使得传统IP网络的流量工程方法不一定适合.为此,本文在SDN(Software Defined Network)的框架下,提出了一种基于链路关键度的自适应负载均衡流量工程方法:DraLCD(Dynamic Routing Algorithm based on Link Critical Degree).该方法通过对全局视图的网络管控,并充分利用了网络中存在的冗余路径,在完成细粒度流量均衡的同时,能够降低控制器的计算开销以及与交换机之间的通信开销,最终完成路由优化的目标.最后,基于DraLCD设计的原型系统,通过在Mininet仿真平台中部署并进行仿真实验,与现有的等开销多路径路由算法ECMP(Equal-Cost Multi-Path)以及GFF(Global First Fit)路由算法相比较,能够明显地提升网络性能.     

Dynamic switch migration with noncooperative game towards control plane scalability in SDN

As software‐defined networking (SDN) is a logically centralized technology, the control plane scalability in SDN is increasingly important with the network scale increasing. Load balancing and maximizing resource utilization are very critical to the control plane in SDN, while switch migration is an effective approach to achieve these two performance metrics. However, switch migration is NP‐hard problem because it belongs to the problem of combinatorial optimization. To avoid the NP‐hard problem, we propose a switch migration scheme by adopting noncooperative game to improve the control plane scalability in SDN. First, we design a novel load balancing monitoring scheme to detect the load imbalance between controllers and trigger migrating switches. Then, we use noncooperative game among controllers to decide switch migration to get the maximizing overall profits. Last, we prove that our proposed approach can get Pareto optimality. Extensive simulations prove that our method is able to achieve a more scalable control plane with load balancing and maximizing resource utilization.     

Emulating Software Defined Network using Mininet-ns3-WIFI Integration for Wireless Networks

SDN enables a new networking paradigm probable to improve system efficiency where complex networks are easily managed and controlled. SDN allows network virtualization and advance programmability for customizing the behaviour of networking devices with user defined features even at run time. SDN separates network control and data planes. Intelligently controlled network management and operation, such that routing is eliminated from forwarding elements (switches) while shifting the routing logic in a centralized module named SDN Controller. Mininet is Linux based network emulator which is cost effective for implementing SDN having in built support of OpenFlow switches. This paper presents practical implementation of Mininet with ns-3 using Wi-Fi. Previous results reported in literature were limited upto 512 nodes in Mininet. Tests are conducted in Mininet by varying number of nodes in two distinct scenarios based on scalability and resource capabilities of the host system. We presented a low cost and reliable method allowing scalability with authenticity of results in real time environment. Simulation results show a marked improvement in time required for creating a topology designed for 3 nodes with powerful resources i.e. only 0.077 sec and 4.512 sec with limited resources, however with 2047 nodes required time is 1623.547 sec for powerful resources and 4615.115 sec with less capable resources respectively.

     

Secure access of resources in software‐defined networks using dynamic access control list

Software‐defined networking (SDN) creates a platform to dynamically configure the networks for on‐demand services. SDN can easily control the data plane and the control plane by implementing the decoupling concept. SDN controller will regulate the traffic flow and creates the new flow label based on the packet dump received from the OpenFlow virtual switches. SDN governs both data information and control information toward the destination based on flow label, but it does not contain security measure to restrict the malicious traffic. The malicious denial‐of‐service (DoS) attack traffic is generated inside the SDN environment; it leads to the service unavailability. This paper is mainly focused on the detection of DoS attacks and also mitigates the malicious traffic by dynamically configuring the firewall. The SDN with dynamic access control list properties is emulated by mininet, and the experimental results exemplify the service unavailable gap between acceptance and rejection ratio of the packets.     

基于流量工程的软件定义网络控制资源优化机制

针对软件定义网络(SDN)分布式控制平面中由于网络分域管理所引发的控制扩张问题,该文提出了一种基于流量工程的SDN控制资源优化(TERO)机制。首先基于数据流的路径特征对流请求的控制资源消耗进行分析,指出通过调整控制器和交换机的关联关系可以降低控制资源消耗。然后将控制器关联过程分为两个阶段:先设计了最小集合覆盖算法来快速求解大规模网络中控制器关联问题;在此基础上,引入联合博弈策略来优化控制器和交换机的关联关系以减少控制资源消耗和控制流量开销。仿真结果表明,与现有的控制器和交换机就近关联机制相比,该文机制能在保证较低控制流量开销的前提下,节省约28%的控制资源消耗。     

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.     

面向软件定义广域网的路径可编程性保障研究综述

软件定义网络(SDN)被誉为下一代网络的关键技术。近年来，SDN已经成为学术界与工业界的热点。广域网是SDN应用到工业界的一个重要的场景。基于SDN的广域网被称为软件定义广域网(SD-WAN)。在SD-WAN中，SDN控制器通过控制流转发路径上的SDN交换机来实现流的路径可编程性。然而，控制器失效是SD-WAN中一种常见的现象。当控制器失效时，流转发路径上的交换机会失去控制，流的路径可编程性将无法得到保障，从而无法实现对网络流量的灵活调度，导致网络性能下降。该文对SD-WAN控制器失效场景下保证路径可编程性的研究工作进行了综述。该文首先阐述了当控制器失效时，SD-WAN中路径可编程性保障研究的背景及意义。随后，在查阅分析了国内外相关文献的基础上，介绍了当前在控制器失效时SD-WAN对交换机的主流控制方案。最后，对现有研究成果可能的进一步提高之处进行了总结，并对此研究的未来发展与研究前景进行了展望。     

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.     

Deep Learning Based Analog Beamforming Design for Millimetre Wave Massive MIMO System

Software-defined networking (SDN) is a new approach that overcomes the obstacles which are faced by conventional networking architecture. The core idea of SDN is to separate the control plane from the data plane. This idea improves the network in many ways, such as efficient utilization of resources, better management of the network, reduced cost, innovation with new evolution, and many others. To manage all these changes, there is a great need for an efficient controller to improve the utilization of resources for the better performance of the network. The controller is also responsible for the analysis and monitoring of real-time data traffic. There is a great need for a high-performance controller in networking industries, data centres, academia, and research due to the tremendous growth of distributed processing-based real time applications. Therefore, it is crucial to investigate the performance of an open-source controller to provide efficient traffic routing, leading to improved utilization of resources for the enhanced performance metrics of the network. The paper presents an implementation of SDN architecture using an open-source RYU SDN controller for the network traffic analysis. The proposed work evaluates the performance of SDN architecture based custom network topology for a node to node performance parameters such as bandwidth, throughput and roundtrip time, etc. The simulation results exhibit an improved performance of the proposed work in comparison to the existing default network topology for SDN.

     

Design and evaluation of inter‐bandwidth broker signaling

Bandwidth brokers (BBs) have been proposed for providing end‐to‐end quality of services (QoS) in differentiated services (Diffserv) networks. As a single entity in each domain, a BB aims at performing both intra‐ and inter‐domain resource management on behalf of its domain. There have been plenty of BB studies for intra‐domain resource management. However, how a BB can perform inter‐domain resource management in a scalable and deployable manner is still an open issue. In this work, we present the design, implementation and evaluation of an inter‐BB communication protocol that is used by each BB to communicate with its neighboring BBs for inter‐domain QoS resource management. The proposed model uses a destination‐based aggregation scheme in which reservations are aggregated as they merge through the destination region. The destination‐based aggregation improves inter‐domain state and signaling scalability. The protocol also performs traffic engineering to increase inter‐domain resource utilization. The implementation and simulation results verify the achievements of our model. Copyright © 2008 John Wiley & Sons, Ltd.     

Toward manageable middleboxes in software‐defined networking

Software‐defined networking (SDN) acts as a centralized management unit, especially in a network with devices that operate under the transport layer of the OSI model. However, when a network with layer 7 middleboxes (MBs) is considered, current SDNs exhibit limitations. As such, to achieve a real‐centralized management unit, a new architecture is required that decouples the data and control planes of all network devices. In this report, we propose such a complementary architecture to the current SDN in which SDN‐enabled MBs are included along with contemporary SDN‐enabled switches. The management unit of this architecture improves network performance and reduces routing cost by considering the status of the MBs during flow forwarding. This unit consists of the following two parts: an SDN controller (SDNC) and a middlebox controller (MBC). The latter selects the best MBs for each flow and the former determines the best path according to its routing algorithm and provides information via the MBC. The results show that the proposed architecture improved performance because the utilization of all network devices including MBs is manageable.     

Dynamic switch migration towards a scalable SDN control plane

Distributed control plane is a promising approach to scalable software‐defined networking (SDN). Live migration of switches from controllers that are overloaded to those that are underutilized may be a solution to handle peak switch traffic using available control resource. However, such migration has to be performed with a well‐designed mechanism to fully utilize available resources in all three resource dimensions: CPU, bandwidth, and memory. In this article, we first provide a resource model for SDN and reduce the switch migration decision to a centralized resource utilization maximization problem under constraints of CPU, bandwidth, and memory. Second, we show that the problem of maximizing resource utilization in an SDN is equivalent to that of maximizing game players' profits in the context of non‐cooperative game theory. Taking controllers and switches as game players and commodities respectively, the player policy is how to migrate switches among the control plane. Finally, we implement a proof of concept, called GAME‐Switch Migration (GAME‐SM). The numerical experiments using Mininet emulator validate nice properties of our game model in enhancing the performance of control plane in SDN. Copyright © 2016 John Wiley & Sons, Ltd.     

Proactive multipath routing with a predictive mechanism in software‐defined networks

With the growth of network traffic volume, link congestion cannot be avoided efficiently with conventional routing protocols. By utilizing the single shortest‐path routing algorithm from link state advertisement information, standard routing protocols lack of global awareness and are difficult to be modified in a traditional network environment. Recently, software‐defined network (SDN) provided innovative architecture for researchers to program their own network protocols. With SDN, we can divert heavy traffic to multiple paths in order to resolve link congestion. Furthermore, certain network traffics come in periodic fashion such as peak hours at working days so that we can leverage forecasting for resource management to improve its performance. In this paper, we propose a proactive multipath routing with a predictive mechanism (PMRP) to achieve high‐performance congestion resolution. PMRP has two main concepts: (a) a proactive mechanism where PMRP deploys M/M/1 queue and traffic statistics to simulate weighted delay for possible combinations of multipaths placement of all subnet pairs, and leverage genetic algorithm for accelerating selection of optimized solution, and (b) a predictive mechanism whereby PMRP uses exponential smoothing for demand traffic volumes and variance predictions. Experimental results show a 49% reduction in average delay as compared with single shortest routing, and a 16% reduction in average delay compared with utilization & topology‐aware multipath routing (UTAMP). With the predictive mechanism, PMRP can decrease an additional 20% average delay. Furthermore, PMRP reduces 93% of flow table usage on average as compared with UTAMP.     

一种基于深度增强学习的智能路由技术

随着网络规模的不断增大以及网络复杂度的不断提高,传统路由算法面对网络流量在时空分布上的剧烈波动难以兼顾计算复杂度和算法效率.近年来,随着软件定义网络和人工智能技术的兴起,基于机器学习的自动路由策略生成逐渐受到关注.本文提出一种基于深度增强学习的智能路由技术SmartPath,通过动态收集网络状态,使用深度增强学习自动生成路由策略,从而保证路由策略能够动态适应网络流量变化.实验结果表明,本文所提出的方案能够不依赖人工流量建模动态更新网络路由,在测试环境下比当前最优方案减少至少10%的平均端到端传输时延.     

SDN‐DMM for intelligent mobility management in heterogeneous mobile IP networks

Mobility management applied to the traditional architecture of the Internet has become a great challenge because of the exponential growth in the number of devices that can connect to the network. This article proposes a Software‐Defined Networking (SDN)‐based architecture, called SDN‐DMM (SDN‐Distributed Mobility Management), that deals with the distributed mode of mobility management in heterogeneous access networks in a simplified and efficient way, ensuring mainly the continuity of IP sessions. Intent‐based mobility management with an IP mapping schema for mobile node identification offers optimized routing without tunneling techniques, hence, an efficient use of the network infrastructure. The simplified mobility control API reduces both signaling and handover latency costs and provides a better scalability and performance in comparison with traditional and SDN‐based DMM approaches. An analytical evaluation of such costs demonstrated the better performance of SDN‐DMM, and a proof of concept of the proposal was implemented in a real environment.     

A scalable model for interbandwidth broker resource reservation and provisioning

As the Internet evolves into global communication and commercial infrastructure, the need for quality-of-services (QoSs) in the Internet becomes more and more important. With a bandwidth broker (BB) support in each administrative domain, differentiated services (Diffserv) is seen as a key technology for achieving QoS guarantees in a scalable, efficient, and deployable manner in the Internet. In this paper, we present a scalable model for inter-BB resource reservation and provisioning. Our BB uses centralized network state maintenance and pipe-based intradomain resource management schemes that significantly reduce admission control time and minimize scalability problems present in prior research. For inter-BB communication, we design and implement a BB resource reservation and provisioning protocol (BBRP). BBRP performs destination-based aggregated resource reservation based on bilateral service level agreements (SLAs) between peer-BBs. BBRP significantly reduces the BB and border routers state scalability problem by maintaining reservation state based only on destination region. It minimizes inter-BB signaling scalability by using aggregated type resource reservation and provisioning. Both analytical and experimental results verify the BBRP achievements.     

A novel four-tier software-defined network architecture for scalable secure routing and load balancing

Software-defined networking is an emerging paradigm for supporting flexible network management. In the traditional architecture for a software-defined network (SDN), the controller commonly uses a general routing algorithm such as Open Shortest Path First (OSPF), which chooses the shortest path for communication. This may cause the largest amount of network traffic, especially in large-scale environments. In this paper, we present the design for a novel SDN-based four-tier architecture for scalable secure routing and load balancing. In Tier 1, user authentication is conducted using elliptic curve cryptography (ECC); this avoids unnecessary loads from unauthorized users. In Tier 2, packet classification is performed based on the packet characteristics using the fuzzy analytical hierarchy process (fuzzy AHP), and packets are placed into three individual queues. In Tier 3, scalable secure routing is achieved by selecting the optimal path using the improved particle swarm optimization and ant colony optimization algorithms. With these optimization algorithms, we can adaptively change the number of users, the number of switches, and other parameters. In Tier 4, the recommended secure cluster (multicontroller) management is accomplished using an algorithm that employs modified k-means clustering and a recurrent neural network. Deep reinforcement learning (DRL) is also proposed for updating the controller information. Experimental results are analyzed using the OMNeT++ network simulator, and the evaluated performance displayed improvement over a variety of existing methods in terms of response time (50% to 60%), load (55%), execution time (3.2%), throughput (9.8%), packet loss rate (1.02%), end-to-end delay (50%), and bandwidth consumption (45%).     

基于动态多网段的数据链网络监视与管理系统的设计与实现

提出了一种可动态配置 IP 跨网段的数据链网络监视管理系统的设计与实现方法， 该系统应用层采用 B/S 与 C/S 的混合架构，网络层通过软件定义网络(SDN)集群实现数据链网内成员间的跨网段交互的动态可配置。系统功能涉及平台身份控制、方案管理、跨网段参数控制、 多网段内节点状态监视等技术。所设计方法的应用结果表明，该系统可以为数据链网络提供可靠的监视与管理服务，任意节点间路由关系动态可配置，提高数据链各节点的灵活性，满足项目应用要求。