To meet the timing requirements of interactive applications, the no-frills congestion-agnostic transport protocols like UDP are increasingly deployed side-by-side in the same network with congestion-responsive TCP. In cloud platforms, even though the computation and storage is totally virtualized, they lack a true virtualization mechanism for the network (i.e., the underlying data centers networks). The impact of such lack of isolation services, may result into frequent outages (for some applications) when such diverse traffics contend for the small buffers in the commodity switches used in data centers. In this paper, we explore the design space of a simple, practical and transport-agnostic scheme to enable a scalable and flexible end-to-end congestion control in data centers. Then, we present the the shortcomings of coupling the monitoring and control of congestion in the conventional system and discuss how a Software-Defined Network (SDN) would provide an appealing alternative to circumvent the problems of the conventional system. The two systems implements a software-based congestion control mechanisms that perform monitoring, control decisions and traffic control enforcement functions. Both systems are designed with a major assumption that the applications (or transport protocols) are non-cooperative with the system, ultimately making it deployable in existing data centers without any service disruption or hardware upgrade. Both systems are implemented and evaluated via simulation in NS2 as well as real-life small-scale test-bed deployment and experiments.
The centralized architecture in software-defined network (SDN) provides a global view of the underlying network, paving the way for enormous research in the area of SDN traffic engineering (SDN TE). This research focuses on the load balancing aspects of SDN TE, given that the existing reactive methods for data-plane load balancing eventually result in packet loss and proactive schemes for data plane load balancing do not address congestion propagation. In the proposed work, the SDN controller periodically monitors flow level statistics and utilization on each link in the network and over-utili…
The short-term adoption of opportunistic networks (OppNet) depends on improving the current performance of this type of network. Software-Defined Networks (SDN) architecture is used by Internet applications with high resource demand. SDN technology improves network performance by programmatically managing the network configuration by using a control layer. In this paper, we propose that OppNet nodes use a control layer to get an overview of the whole network and use this knowledge to apply policies to get a better performance of the network. As a use case for our experimentation, we have focus…
To improve traffic management ability, Internet Service Providers (ISPs) are gradually upgrading legacy network devices to programmable devices that support Software-Defined Networking (SDN). The coexistence of legacy and SDN devices gives rise to a hybrid SDN. Existing hybrid SDNs do not consider the potential performance issues introduced by a centralized SDN controller: flow requests processed by a highly loaded controller may experience long tail processing delay; inappropriate multi-controller deployment could increase the propagation delay of flow requests. In this paper, we propose to j…
For software-defined networking (SDN) systems, to enhance the scalability and reliability of control plane, existing solutions adopt either multi-controller design with static switch-controller associations, or static control devolution by delegating certain request processing back to switches. Such solutions can fall short in face of temporal variations of request traffics, incurring considerable local computation costs on switches and their communication costs to controllers. So far, it still remains an open problem to develop a joint online scheme that conducts dynamic switch-controller ass…
In Software-Defined Networking (SDN), network applications use the logically centralized network view provided by the controller to remotely orchestrate the network switches. To avoid the controller being a single point of failure, traditional fault-tolerance techniques are employed to guarantee availability, a fundamental requirement in production environments. Unfortunately, these techniques fall short of ensuring correct network behaviour under controller failures. The problem of these techniques is that they deal with only part of the problem: guaranteeing that application and controller s…
In software-defined networking (SDN) systems, it is a common practice to adopt a multi-controller design and control devolution techniques to improve the performance of the control plane. However, in such systems, the decision-making for joint switch-controller association and control devolution often involves various uncertainties, e.g., the temporal variations of controller accessibility, and computation and communication costs of switches. In practice, statistics of such uncertainties are unattainable and need to be learned in an online fashion, calling for an integrated design of learning …
Networking for big data has to be intelligent because it will adjust data transmission requirements adaptively during data splitting and merging. Software-defined networking (SDN) provides a workable and practical paradigm for designing more efficient and flexible networks. Matching strategy in the flow table of SDN switches is most crucial. In this paper, we use a classification approach to analyze the structure of packets based on the tuple-space lookup mechanism, and propose a matching model of the flow table in SDN switches by classifying packets based on a set of fields, which is called a…
Software-defined networking (SDN) is an architecture that aims to make networks fast and flexible. SDN's goal is to improve network control by enabling service providers as well as enterprises to respond quickly to changing business needs. In SDN, the administrator can shape traffic from a centralized control console without having to modify any of the individual switches belonging to the network. The SDN controller which is centralized directs the switches to deliver network services wherever they are needed, irrespective of the specific connections between a server and devices. This methodol…
We propose P4-MACsec to protect network links between P4 switches through automated deployment of MACsec, a widespread IEEE standard for securing Layer 2 infrastructures. It is supported by switches and routers from major manufacturers and has only little performance limitations compared to VPN technologies such as IPsec. P4-MACsec introduces a data plane implementation of MACsec including AES-GCM encryption and decryption directly on P4 switches. P4-MACsec features a two-tier control plane structure where local controllers running on the P4 switches interact with a central controller. We prop…
Current approaches to tackle the single point of failure in SDN entail a distributed operation of SDN controller instances. Their state synchronization process is reliant on the assumption of a correct decision-making in the controllers. Successful introduction of SDN in the critical infrastructure networks also requires catering to the issue of unavailable, unreliable (e.g. buggy), and malicious controller failures. We propose MORPH, a framework tolerant to unavailability and Byzantine failures, which distinguishes and localizes faulty controller instances and appropriately reconfigures the c…
Future cellular networks will be dense and require key traffic management technologies for fine-grained network control. The problem gets more complicated in the presence of different network segments with bottleneck links limiting the desired quality of service (QoS) delivery to the last mile user. In this work, we first design a framework for software-defined cellular networks (SDCN) and then propose new mechanisms for management of QoS and non-QoS users traffic considering both access and backhaul networks, jointly. The overall SDN-LTE system and related approaches are developed and tested …
Modern In-Vehicle Networks (IVNs) are composed of a large number of devices and services linked via an Ethernet-based time-sensitive network. Communication in future IVNs will become more dynamic as services can be updated, added, or removed during runtime. This requires a flexible and adaptable IVN, for which Software-Defined Networking (SDN) is a promising candidate. In this paper, we show how SDN can be used to support a dynamic, service-oriented network architecture. We demonstrate our concept using the SOME/IP protocol, which is the most widely deployed implementation of automotive servic…
Network performance monitoring holds a pivotal role in improving the overall network performance. It is essential to monitor the traffic statistics at Internet eXchange Points (IXPs) to optimize the traffic flows. The existing monitoring system either lacks usability or programmability. We present a Software Defined Networking (SDN) enabled and OpenFlow (OF) compatible network performance monitoring system (SDX-Manager) to improve the usability or programmability of IXP simultaneously. The proposed system integrates traditional IXP-Manager with the SDN controller and Grafana to better visualiz…
Wireless connectivity for the Internet of Things (IoT) requires combining low latency and high reliability with power and cost constraints. On top of that, diverse applications and end-to-end services with very different performance requirements should ideally share the same network infrastructure. Software defined networks (SDN) were defined to allow this coexistence, but they have seen very limited adoption in IoT systems due to the inherent resource constrained nature of the wireless devices. Additionally, the low-power nature of IoT communication standards does not usually allow for physic…
主动测量对于网络的运行和管理是不可或缺的，并且对于支持经验网络研究是非常宝贵的。不幸的是，广泛部署测量节点，特别是在核心中，通常是成本高昂且后勤困难的。在这项工作中，我们考虑了通过使用软件定义网络（SDN）在基础设施内紧密集成测量的可行性。我们引入了“SDN as Active Measurement Infrastructure”（SAAMI），使测量能够从部署SDN的任何位置发起，从而消除了对专用测量节点的需求，并增加了优势点的多样性。我们使用SAAMI实现ping和traceroute，以及一个概念验证的自定义测量协议，以展示SAAMI开放式框架的强大功能和易用性。通过使用SDN交换机作为有利位置的大规模测量活动，我们表明SAAMI是准确的，可扩展的和可扩展的。
Software Defined Networking (SDN) is an emerging technology of efficiently controlling and managing computer networks, such as in data centres, Wide Area Networks (WANs), as well as in ubiquitous communication. In this paper, we explore the idea of embedding the SDN components, represented by SDN controller and virtual switch, in end-hosts to improve network performance. In particular, we consider load balancing across multiple network interfaces on end-hosts with different link capacity scenarios. We have explored and implemented different SDN-based load balancing approaches based on OpenFlow…
Data communication in cloud-based distributed stream data analytics often involves a collection of parallel and pipelined TCP flows. As the standard TCP congestion control mechanism is designed for achieving "fairness" among competing flows and is agnostic to the application layer contexts, the bandwidth allocation among a set of TCP flows traversing bottleneck links often leads to sub-optimal application-layer performance measures, e.g., stream processing throughput or average tuple complete latency. Motivated by this and enabled by the rapid development of the Software-Defined Networking (SD…
Distributed Software Defined Networking (SDN) controllers aim to solve the issue of single-point-of-failure and improve the scalability of the control plane. Byzantine and faulty controllers, however, may enforce incorrect configurations and thus endanger the control plane correctness. Multiple Byzantine Fault Tolerance (BFT) approaches relying on Replicated State Machine (RSM) execution have been proposed in the past to cater for this issue. The scalability of such solutions is, however, limited. Additionally, the interplay between progressing the state of the distributed controllers and the …
Failures in networks result in service disruptions which may cause deteriorated Quality of Service (QoS) for the end users. Since SDN is becoming the mainstream paradigm for networks, implementation of a robust fault tolerance scheme for SDN-based networks is crucial. Existing SDN data plane fault tolerance approaches can be classified as reactive and proactive which may or may not rely on the controller, respectively. However, none of them qualifies as a complete solution, providing only partial remedies. In this work, we propose Dynamic Protection with Quality of Alternative Paths (DPQoAP) t…
Software-defined networking (SDN) has become a fundamental technology for data centers and 5G networks. In an SDN network, routing and traffic management decisions are made by a centralized controller and communicated to switches via a control channel. Transport Layer Security (TLS) has been proposed as its single security layer; however, use of TLS is optional and connections are still vulnerable to downgrade attacks. In this paper, we propose the strengthening of security assurance using a protocol dialecting approach to provide additional and customizable security. We consider and evaluate …
SDN-enabled Integrated satellite-terrestrial networks (ISTNs), can provide several advantages including global seamless coverage, high reliability, low latency, etc. and can be a key enabler towards next generation networks. To deal with the complexity of the control and management of the integrated network, leveraging the concept of software-defined networking (SDN) will be helpful. In this regard, the SDN controller placement problem in SDN-enabled ISTNs becomes of paramount importance. In this paper, we formulate an optimization problem for the SDN controller placement with the objective of…
The communication network context in actual systems like 5G, cloud and IoT (Internet of Things), presents an ever-increasing number of users, applications, and services that are highly distributed with distinct and heterogeneous communications requirements. Resource allocation in this context requires dynamic, efficient, and customized solutions and Bandwidth Allocation Models (BAMs) are an alternative to support this new trend. This paper proposes the BAMSDN (Bandwidth Allocation Model through Software-Defined Networking) framework that dynamically allocates resources (bandwidth) for a MPLS (…
LineSwitch: Efficiently Managing Switch Flow in Software-Defined Networking while Effectively Tackling DoS Attacks
软件定义网络（Software Defined Networking，SDN）是一种新的网络架构，旨在提供网络控制（控制平面）和数据转发功能（数据平面）之间更好的解耦。这种分离带来了几个好处，例如直接可编程和（虚拟）集中式网络控制。然而，研究人员表明，SDN的控制和数据平面之间所需的通信通道在系统中产生了潜在的瓶颈，引入了新的漏洞。事实上，这种行为可能被用来发动强大的攻击，例如控制平面饱和攻击，这可能严重阻碍整个网络的性能。本文提出了一种有效的抗控制平面饱和攻击的解决方案LineSwitch。LineSwitch结合了SYN代理技术和网络流量的概率黑名单。我们实现了LineSwitch作为OpenFlow的扩展，OpenFlow是SDN的当前参考实现，并考虑不同的流量场景（有和没有攻击）评估我们的解决方案。我们的初步实验结果证实，与最先进的技术相比，LineSwitch将时间开销减少了30%，同时确保了相同的保护水平。
In this paper, we propose a destination-aware adaptive traffic flow rule aggregation (DATA) mechanism for facilitating traffic flow monitoring in SDN-based networks. This method adapts the number of flow table entries in SDN switches according to the level of detail of traffic flow information that other mechanisms (e.g. for traffic engineering, traffic monitoring, intrusion detection) require. It also prevents performance degradation of the SDN switches by keeping the number of flow table entries well below a critical level. This level is not preset as a hard threshold but learned during oper…
