Horizontal-Based Orchestration for Multi-Domain SFC in SDN/NFV-Enabled Satellite/Terrestrial Networks

It's promising to use Software-Defined Networking(SDN) and Network Functions Virtualization(NFV) to integrate satellite and terrestrial networks. To construct network service function chains in such a multi-domain environment, we propose a horizontal-based Multi-domain Service Function Chaining(Md-SFC) orchestration framework. In this framework, multi-domain orchestrators can coordinate with each other to guarantee the end-to-end service quality. Intra-domain orchestrators also coordinate SDN controllers and NFV management components to implement intra-domain service function chains. Based on this, we further propose a heuristic SFC mapping algorithm with a cooperative inter-domain path calculation method to map service function chains to infrastructures. In this method, master multi-domain orchestrator and intra-domain orchestrators coordinate to select proper inter-domain links. We compare the cooperative method with a naive uncooperative way that domains' topology information is provided to the master multi-domain orchestrator and it calculates the shortest inter-domain path between intra-domain service function chains directly. Simulation results demonstrate that our solution is feasible. It is able to construct end-to-end performance guaranteed service function chain by horizontal-based cooperation. The cooperative inter-domain path calculation method decreasesthe mapping load for the master orchestrator and gets the same end-to-end performance.

A PSO Based Multi-Domain Virtual Network Embedding Approach

This paper proposed a multi-domain virtual network embedding algorithm based on multi-controller SDN architecture. The local controller first selects candidate substrate nodes for each virtual node in the domain. Then the global controller abstracts substrate network topology based on the candidate nodes and boundary nodes of each domain, and applies Particle Swarm Optimization Algorithm on it to divide virtual network requests. Each local controller then embeds the virtual nodes of the divided single-domain virtual network requests in the domain, and cooperates with other local controllers to embed the inter-domain virtual links. Simulation experimental results show that the proposed algorithm has good performance in reducing embedding cost with good stability and scalability.

Virtual 5G Network Embedding in a Heterogeneous and Multi-Domain Network Infrastructure

The pursuit of the higher performance mobile communications forces the emergence of the fifth generation mobile communication(5G). 5G network, integrating wireless and wired domain, can be qualified for the complex virtual network work oriented to the cross-domain requirement. In this paper, we focus on the multi-domain virtual network embedding in a heterogeneous 5G network infrastructure, which facilitates the resource sharing for diverse-function demands from fixed/mobile end users. We proposed the mathematical ILP model for this problem.And based on the layered-substrate-resource auxiliary graph and an effective six-quadrant service-type-judgment method, 5G embedding demands can be classified accurately to match different user access densities. A collection of novel heuristic algorithms of virtual 5G network embedding are proposed. A great deal of numerical simulation results testified that our algorithm performed better in terms of average blocking rate, routing latency and wireless/wired resource utilization, compared with the benchmark.

SDN Orchestration for Dynamic End-to-End Control of Data Center Multi-Domain Optical Networking

New and emerging use cases, such as the interconnection of geographically distributed data centers(DCs), are drawing attention to the requirement for dynamic end-to-end service provisioning, spanning multiple and heterogeneous optical network domains. This heterogeneity is, not only due to the diverse data transmission and switching technologies, but also due to the different options of control plane techniques. In light of this, the problem of heterogeneous control plane interworking needs to be solved, and in particular, the solution must address the specific issues of multi-domain networks, such as limited domain topology visibility, given the scalability and confidentiality constraints. In this article, some of the recent activities regarding the Software-Defined Networking(SDN) orchestration are reviewed to address such a multi-domain control plane interworking problem. Specifically, three different models, including the single SDN controller model, multiple SDN controllers in mesh, and multiple SDN controllers in a hierarchical setting, are presented for the DC interconnection network with multiple SDN/Open Flow domains or multiple Open Flow/Generalized Multi-Protocol Label Switching( GMPLS) heterogeneous domains. I n addition, two concrete implementations of the orchestration architectures are detailed, showing the overall feasibility and procedures of SDN orchestration for the end-to-endservice provisioning in multi-domain data center optical networks.

Virtualized Wireless SDNs:Modelling Delay Through the Use of Stochastic Network Calculus

Software-defined networks （SDN） have attracted much attention recently because of their flexibility in terms of network management. Increasingly, SDN is being introduced into wireless networks to form wireless SDN. One enabling technology for wireless SDN is network virtualization, which logically divides one wireless network element, such as a base station, into multiple slices, and each slice serving as a standalone virtual BS. In this way, one physical mobile wireless network can be partitioned into multiple virtual networks in a software-defined manner. Wireless virtual networks comprising virtual base stations also need to provide QoS to mobile end-user services in the same context as their physical hosting networks. One key QoS parameter is delay. This paper presents a delay model for software-defined wireless virtual networks. Network calculus is used in the modelling. In particular, stochastic network calculus, which describes more realistic models than deterministic network calculus, is used. The model enables theoretical investigation of wireless SDN, which is largely dominated by either algorithms or prototype implementations.

SDN Based Next Generation Mobile Network With Service Slicing and Trials

Software-Defined Network （SDN） empowers the evolution of Internet with the OpenFlow, Network Virtualization and Service Slicing strategies. With the fast increasing requirements of Mobile Internet services, the Internet and Mobile Networks go to the convergence. Mobile Networks can also get benefits from the SDN evolution to fulfill the 5th Generation （5G） capacity booming. The article implements SDN into Frameless Network Architecture （FNA） for 5G Mobile Network evolution with proposed Mobile-oriented OpenFlow Protocol （MOFP）. The Control Plane/User Plane （CP/UP） separation and adaptation strategy is proposed to support the User-Centric scenario in FNA. The traditional Base Station is separated with Central Processing Entity （CPE） and Antenna Element （AE） to perform the OpenFlow and Network Virtualization. The AEs are released as new resources for serving users. The mobile-oriented Service Slicing with different Quality of Service （QoS） classification is proposed and Resource Pooling based Virtualized Radio Resource Management （VRRM） is optimized for the Service Slicing strategy with resource-limited feature in Mobile Networks. The capacity gains are provided to show the merits of SDN based FNA. And the MiniNet based Trial Network with Service Slicing is implemented with experimental results.

Robust Virtual Network Embedding Based on Component Connectivity in Large-Scale Network

Virtual network embedding problem which is NP-hard is a key issue for implementing software-defined network which is brought about by network virtualization. Compared with other studies which focus on designing heuristic algorithms to reduce the hardness of the NP-hard problem we propose a robust VNE algorithm based on component connectivity in large-scale network. We distinguish the different components and embed VN requests onto them respectively. And k-core is applied to identify different VN topologies so that the VN request can be embedded onto its corresponding component. On the other hand, load balancing is also considered in this paper. It could avoid blocked or bottlenecked area of substrate network. Simulation experiments show that compared with other algorithms in large-scale network, acceptance ratio, average revenue and robustness can be obviously improved by our algorithm and average cost can be reduced. It also shows the relationship between the component connectivity including giant component and small components and the performance metrics.

Virtualizing Network and Service Functions: Impact on ICT Transformation and Standardization

Virtualization of network/service functions means time sharing network/service（and affiliated）resources in a hyper speed manner.The concept of time sharing was popularized in the 1970s with mainframe computing.The same concept has recently resurfaced under the guise of cloud computing and virtualized computing.Although cloud computing was originally used in IT for server virtualization,the ICT industry is taking a new look at virtualization.This paradigm shift is shaking up the computing,storage,networking,and ser vice industries.The hope is that virtualizing and automating configuration and service management/orchestration will save both capes and opex for network transformation.A complimentary trend is the separation（over an open interface）of control and transmission.This is commonly referred to as software defined networking（SDN）.This paper reviews trends in network/service functions,efforts to standardize these functions,and required management and orchestration.

Performance Evaluation of Topologies for Multi-Domain Software-Defined Networking

Software-defined networking(SDN)is widely used in multiple types of data center networks,and these distributed data center networks can be integrated into a multi-domain SDN by utilizing multiple controllers.However,the network topology of each control domain of SDN will affect the performance of the multidomain network,so performance evaluation is required before the deployment of the multi-domain SDN.Besides,there is a high cost to build real multi-domain SDN networks with different topologies,so it is necessary to use simulation testing methods to evaluate the topological performance of the multi-domain SDN network.As there is a lack of existing methods to construct a multi-domain SDN simulation network for the tool to evaluate the topological performance automatically,this paper proposes an automated multi-domain SDN topology performance evaluation framework,which supports multiple types of SDN network topologies in cooperating to construct a multi-domain SDN network.The framework integrates existing single-domain SDN simulation tools with network performance testing tools to realize automated performance evaluation of multidomain SDN network topologies.We designed and implemented a Mininet-based simulation tool that can connect multiple controllers and run user-specified topologies in multiple SDN control domains to build and test multi-domain SDN networks faster.Then,we used the tool to perform performance tests on various data center network topologies in single-domain and multi-domain SDN simulation environments.Test results show that Space Shuffle has the most stable performance in a single-domain environment,and Fat-tree has the best performance in a multi-domain environment.Also,this tool has the characteristics of simplicity and stability,which can meet the needs of multi-domain SDN topology performance evaluation.

Optimize the Deployment and Integration for Multicast-Oriented Virtual Network Function Tree

Due to the development of network technology,the number of users is increasing rapidly,and the demand for emerging multicast services is becoming more and more abundant,traffic data is increasing day by day,network nodes are becoming denser,network topology is becoming more complex,and operators’equipment operation and maintenance costs are increasing.Network functions virtualization multicast issues include building a traffic forwarding topology,deploying the required functions,and directing traffic.Combining the two is still a problem to be studied in depth at present,and this paper proposes a two-stage solution where the decisions of these two stages are interdependent.Specifically,this paper decouples multicast traffic forwarding and function delivery.The minimum spanning tree of traffic forwarding is constructed by Steiner tree,and the traffic forwarding is realized by Viterbi-algorithm.Use a general topology network to examine network cost and service performance.Simulation results show that this method can reduce overhead and delay and optimize user experience.

On Effective Virtual Networks Interconnection

The network services today require extremely agile and mobile, however, the traditional IP infrastructures are so rigid that cannot fit services well. A way should be put forward to automate the network to improve responsiveness to change. SDN and network virtualization(NV) are two hottest approaches to make networking more automated and scalable to support virtualized and cloud environments. Network virtualization combines hardware and software network resources and network functionality into a single virtual network. SDN is created to simplify traffic management and achieve operational efficiencies by establish and exercising central control over packet forwarding. In this paper, we focus on the situation where SDN controller needs to connect two virtual networks temporarily. We put forward three algorithms to try to make this connection more effective and evaluate these three algorithms.

Service Function Chain Migration in LEO Satellite Networks

With the advancements of software defined network(SDN)and network function virtualization(NFV),service function chain(SFC)placement becomes a crucial enabler for flexible resource scheduling in low earth orbit(LEO)satellite networks.While due to the scarcity of bandwidth resources and dynamic topology of LEO satellites,the static SFC placement schemes may cause performance degradation,resource waste and even service failure.In this paper,we consider migration and establish an online migration model,especially considering the dynamic topology.Given the scarcity of bandwidth resources,the model aims to maximize the total number of accepted SFCs while incurring as little bandwidth cost of SFC transmission and migration as possible.Due to its NP-hardness,we propose a heuristic minimized dynamic SFC migration(MDSM)algorithm that only triggers the migration procedure when new SFCs are rejected.Simulation results demonstrate that MDSM achieves a performance close to the upper bound with lower complexity.

基于OpenFlow的SDN技术研究

软件定义网络(software-defined networking,简称SDN)技术分离了网络的控制平面和数据平面,为研发网络新应用和未来互联网技术提供了一种新的解决方案.综述了基于OpenFlow的SDN技术发展现状,首先总结了逻辑控制和数据转发分离架构的研究背景,并介绍了其关键组件和研究进展,包括OpenFlow交换机、控制器和SDN技术,然后从4个方面分析了基于OpenFlow的SDN技术目前所面临的问题和解决思路.结合近年来的发展现状,归纳了在校园网、数据中心以及面向网络管理和网络安全方面的应用,最后探讨了未来的研究趋势.

电信IP网向SDN演进的探讨

SDN提出了面向下一代IP网络的全新架构,以适应网络技术和应用的创新发展,为传统网络演进和变革指明了方向。对当前电信IP网面临的问题进行了阐述,介绍了SDN架构及基本特征,对SDN满足电信级要求的网络性能、网络扩展性、网络生存性3个方面进行了探讨和分析,并结合电信运营商网络现实需求,探索SDN在电信网的应用与实践。

基于SDN的跨数据中心承载技术

互联网产业的发展和云计算的兴起催生了跨数据中心互联的需求,而软件定义网络技术为解决数据中心互联的网络瓶颈提供了重要途径。首先介绍了几种常用的数据中心互联技术,分析了SDN的技术优势,然后提出了一种基于SDN的运营商数据中心互联承载技术方案,并阐述其实现思路。该方案可实现DC间的网络虚拟化,能够提供用户业务定制、网络自动开通、任意虚拟机间的策略隔离、流量调度、用户就近访问、DC间的容灾备份等业务功能。

基于软件定义价格的SDN应用体系结构

首先,从用户付费调用网络资源的角度提出了SDN应用概念;接着,通过对比传统的桌面应用编程、传统的网络编程和SDN应用编程,描述了SDN应用编程的优越性;然后,提出了软件定义价格的概念,综合说明了SDN应用的特点,设计了基于软件定义价格的SDN应用框架,并将其应用于Open Daylight开源项目;最后,给出了基于软件定义价格的虚拟租户网络测试案例。实验表明,用户可根据软件定义价格自主选择所需的虚拟租户网络。

SDN/NFV技术的接入网应用

针对宽带接入网在网络建设、运行维护、用户体验和业务经营等领域面临的困难和挑战,以降低接入网的建设成本和维护成本,提升用户体验,促进业务创新为目标,研究了基于虚拟化、集中管控、能力开放等特征的下一代宽带接入网的系统架构、主要应用场景以及所涉及的关键技术。

云环境下面向“虚实融合”网络的SDN构建方法

在网络仿真实验场景的构建中,复杂实体终端难以实现虚拟仿真,需要对实体终端进行接入,但现有接入方式部署复杂、网络性能存在瓶颈、不能适用于大规模网络场景。为有效解决上述问题,提出了一种基于SDN(softwaredefined-network)的虚实融合网络仿真构建方法,利用SDN控制器结合流表构造算法实现对虚实网络的链路管理和数据连通,并设计开发了一套用于虚实融合网络仿真的原型系统,通过SDN控制器实现云平台中虚拟实例与云外实体终端共同组网,构建虚实融合的网络仿真实验场景。利用该原型系统,实验证明了基于SDN的网络仿真方法可以实现云平台中虚拟实例与实体终端高效大规模组网,且具有良好的网络性能。

面向SDN的虚拟网络映射算法研究

针对虚拟网络的映射问题,提出一种在SDN环境下基于蚁群混合遗传算法的虚拟网络映射方法。通过建立线性规划模型,将映射过程分为节点映射和链路映射,首先基于该融合算法将虚拟节点映射到物理节点上,再利用最短路径算法将虚拟链路映射到物理链路上,以此提高虚拟网络请求的接受率。仿真实验结果表明,与D-ViNE、R-ViNE以及RW-BFS相比,蚁群混合遗传算法能有效地将虚拟网络请求的接受率提高10%,并较好地改善了节点和链路的平均利用率以及映射的收益成本比值。

基于NFV与SDN的未来接入网虚拟化关键技术

面对未来移动通信网络中服务需求与成本矛盾带来的压力,集中式接入网是解决上述问题的有效途径。虚拟化技术是实现集中式接入网应用、提升集中式接入网性能的关键。文章阐述计算机领域与移动通信领域的虚拟化技术,给出未来移动通信领域虚拟化技术的分类与需求,基于网络功能虚拟化与软件定义网络,分析集中式接入网架构中的虚拟化技术,从资源共享隔离、覆盖与承载分离的灵活功能配置以及虚拟化技术验证平台等方面,对基于NFV与SDN的集中式接入网虚拟化进行探讨。