Unified Control Plane Research Articles

X-Stor: A Cloud-Native NoSQL Database Service with Multi-Model Support

In recent years at Tencent, we have observed that the use of multiple NoSQL databases for storing business data with diverse models has led to increased programming and deployment costs, as well as inefficient maintenance and underutilized resources. In this paper, we report X-Stor, a cloud-native NoSQL database system that supports multiple data models by extending different storage engines and efficiently managing them through a unified control plane. This design significantly reduces expenses and enables rapid expansion of new models, while seamlessly supporting their complete functionality through storage engine extensions. By consolidating multi-tenant services and data models on the same physical machines, X-Stor significantly enhances the utilization of cluster resources. Additionally, X-Stor introduces a standardized metric called Request Unit (RU) to measure tenant resource consumption for consumption-based pricing purposes. Leveraging this metric, we design RU-based resource management strategies and achieve efficient multi-tenant resource isolation and system load balancing. Currently, X-Stor manages a storage capacity of over 12PB for online operational data, including more than 100,000 tables with multiple data models. It handles 700 billion requests per day with a peak of 30 million requests per second. We evaluate the performance of X-Stor on popular benchmarks and production workloads. The results show that X-Stor performs well under diverse data models.

SDN-Based Service Mobility Management in MEC-Enabled 5G and Beyond Vehicular Networks

The next-generation mobile cellular networks are dedicated to providing a valued and unique service experience by supporting ultrareliable and low-latency communication (URLLC), high throughput, and high availability. Multiaccess edge computing (MEC) is an emerging network solution that provides services and computing functions on edge nodes to provide users with a reliable and high-quality service experience. However, achieving satisfactory Quality of Service (QoS) for diverse service requests in a mobile environment is challenging because of the densely deployed yet resource-constrained MEC servers. A solution to ensure continued service quality is to migrate the services according to the mobility of users. However, in a highly mobile environment such as vehicular communications, this may result in a repeated relocation of services, incurring high operational costs and poor utilization of network resources. Moreover, each service has its own set of communication requirements, such as delay and bandwidth. Meeting these requirements in a highly dynamic and complex vehicular environment is an exacting challenge. Software-defined networking (SDN) concepts are leveraged in MEC to provide a unified control plane interface that performs effective network and service mobility management, to manage the heterogeneity of service requests within the resource-constrained MEC servers. We conducted various Proof-of-Concept (PoC) experiments in an overlapped vehicle-to-everything (V2X) networking environment to demonstrate the feasibility of our proposed system that ensures interconnection and federation among distributed MEC servers and mobile networks.

Cell Traffic Prediction Based on Convolutional Neural Network for Software-Defined Ultra-Dense Visible Light Communication Networks

With the explosive growth of ubiquitous mobile services and the advent of the 5G era, ultra-dense wireless network (UDN) architectures have entered daily production and life. However, the massive access capacity provided by 5G networks and the dense deployment of micro base stations also bring challenges such as high energy consumption, high maintenance costs, and inflexibility. Fiber-based visible light communication (FVLC) has the advantages of large bandwidth and high speed, which provides an efficient connection option for UDN. Thus, in order to make up for the poor flexibility of UDN, we propose a new FVLC-UDN architecture based on software-defined networks (SDNs). Specifically, SDN decouples the data plane and the control plane of the device and centralizes the control of the LED in the cell through a unified control plane, which can not only improve the resource allocation ability of the network but also transmit the data only as the data plane, reducing the manufacturing and implementation costs of the LED. In order to get a better resource allocation scheme, this paper proposes a model for predicting cell traffic based on convolutional neural networks. By predicting the traffic of each cell in the control domain, the traffic trend and cells’ status in the future period of time in the control domain can be obtained, so that a much more efficient resource allocation scheme can be formulated proactively to reduce energy consumption and balance communication loads. The experimental results show that on the real cell traffic dataset, this method is better than the existing prediction methods when the size of training dataset is limited.

SDN-Based Resource Management for Autonomous Vehicular Networks: A Multi-Access Edge Computing Approach

Enabling HD-map-assisted cooperative driving among CAVs to improve navigation safety faces technical challenges due to increased communication traffic volume for data dissemination and an increased number of computing/storing tasks on CAVs. In this article, a new architecture that combines MEC and SDN is proposed to address these challenges. With MEC, the interworking of multiple wireless access technologies can be realized to exploit the diversity gain over a wide range of radio spectrum, and at the same time, computing/storing tasks of a CAV are collaboratively processed by servers and other CAVs. By enabling NFV in MEC, different functions can be programmed on the server to support diversified AV applications, thus enhancing the server's flexibility. Moreover, by using SDN concepts in MEC, a unified control plane interface and global information can be provided, and by subsequently using this information, intelligent traffic steering and efficient resource management can be achieved. A case study is presented to demonstrate the effectiveness of the proposed architecture.

Monitoring and Physical-Layer Attack Mitigation in SDN-Controlled Quantum Key Distribution Networks

Quantum key distribution (QKD) has been identified as a secure method for providing symmetric keys between two parties based on the fundamental laws of quantum physics, making it impossible for a third party to copy the quantum states exchanged without being detected by the sender (Alice) and receiver (Bob) and without altering the original states. However, when QKD is applied in a deployed optical network, physical-layer intrusions may occur in the optical links by injecting harmful signals directly into the optical fiber. This can have a detrimental effect on the key distribution and eventually lead to its disruption. On the other hand, network architectures with software-defined networking (SDN) benefit from a homogeneous and unified control plane that can seamlessly control a QKD-enabled optical network end-to-end. There is no need for a separate QKD control, a separate control for each segment of an optical network, and an orchestrator to coordinate between these parts. Furthermore, SDN allows customized and application-tailored control and algorithm provisioning, such as QKD-aware optical path computation, to be deployed in the network, independent of the underlying infrastructure. Therefore, in this paper, we investigate the integration of the application, SDN, and QKD infrastructure layers and confirm capability for flexible supervision and uninterrupted key service provisioning in the event of link level attacks. An experimental demonstrator is used, for the first time, to verify the architecture proposed, considering real-time monitoring of quantum parameters and fiberoptic link intruders to emulate real-world conditions. Furthermore, attacks on a standard single-mode fiber (via a 3 dB coupler) and a multicore fiber (via an adjacent core) are undertaken to explore different connectivity between QKD units. Results show additional attacker identification and switching time of less than 60 ms for the link cases investigated, being negligible compared to the total (re-)initialization time of 14 min of the QKD units.

Algorithmic and Complexity Aspects of Path Computation in Multi-Layer Networks

Carrier-grade networks comprise several layers where different protocols coexist. Nowadays, most of these networks have different control planes to manage routing on different layers, leading to a suboptimal use of the network resources and to additional operational costs. However, some routers are able to encapsulate, decapsulate, and convert protocols, and act as a liaison between these layers. A unified control plane would be useful to optimize the use of the network resources and to automate the routing configurations. Software-defined networking-based architectures offer an opportunity to design such a control plane. One of the most important problems to deal with in this design is the path computation process. Classical path computation algorithms cannot resolve the problem, as they do not take into account encapsulations and conversions of protocols. In this paper, we propose algorithms to solve this problem and study several cases. If there is no bandwidth constraint, we propose a polynomial algorithm that computes the optimal path. We also give lower and upper bounds on the optimal path length. On the other hand, we show that the problem is $\mathsf {NP}$ -hard if there is a bandwidth constraint (or other quality-of-service parameters), even if there is only two protocols and in a symmetric graph. We study the complexity and the scalability of our algorithms and evaluate their performances on real and random topologies. The results show that they are faster than the previous ones proposed in the literature. These algorithms can also have important applications in automatic tunneling.

SDOWN: A novel algorithm for better Quality of Service and Experience in Software Defined Optical Wireless Network

There is manifold increase in global Internet traffic with the advancement of time and provision of ubiquitous Internet access efficiently in terms of Quality of Service and Experience (QoS and QoE) is a serious challenge for the service provider with existing conventional network technology. With Software Defined Optical Wireless Networking (SDOWN) technology world seems to move toward the Next Generation Network (NGN) which exposes itself to resolve many limitations of a conventional/traditional manually operated optical-wireless network via software-assisted and efficient network control through centralized controller. In this research paper, a layered and logical architecture of the proposed SDOWN model and mathematical analysis are presented. The paper also elucidates the implementation of SDOWN model with and without SDOWN Controller with the help of block and state diagrams. Besides, in this model OpenFlow (OF) governed six (06) MATLAB components has been designed such as SDOWN Controller, Ethernet switch-1 & 2, Optical switch-1 & 2, and Wi-Fi access point with suitable interfaces. Software Defined Networking (SDN) Controller interfacing with optical-wireless network i.e. SDOWN and its performance analysis have been carried out with the state-of-the-art (SotA), where pseudo codes of algorithms and flowcharts for the same are duly explained, which provides Unified Control Plane (UCP) via SDOWN Controller for better QoS and QoE. Simulation results and discussions with suitable Figures have also been presented.

Programmable control plane for mission critical wireless networks

The control plane is an essential element to manage the data plane communications in wired and wireless networks. In a traditional network architecture, the control plane is embedded in the hardware and it lacks programmability. Military wireless networks are historically heterogeneous in nature and require complicated manual setups to create interoperability because of a discontinuous control plane. In the present work, we describe a simple programmable control plane model along with associated network abstractions to create a unified control plane interface that can communicate across heterogeneous wireless networks. We chose an ns-3 based network simulation engine to create, test, and validate the functional fidelity of our models. In addition to the network objects and interfaces available in ns-3, we modified ns-3 codes to capture the characteristics of our proposed model. Furthermore, we proposed a tractable mathematical framework to optimize the performance of the proposed control plane model.

5G‐XHaul: a converged optical and wireless solution for 5G transport networks

AbstractThe common European Information and Communications Technology sector vision for 5G is that it should leverage on the strengths of both optical and wireless technologies. In the 5G context, a wide spectra of radio access technologies—such as millimetre wave transmission, massive multiple‐input multiple‐output and new waveforms—demand for high capacity, highly flexible and convergent transport networks. As the requirements imposed on future 5G networks rise, so do the challenges in the transport network. Hence, 5G‐XHaul proposes a converged optical and wireless transport network solution with a unified control plane based on software defined networking. This solution is able to support the flexible backhaul and fronthaul—X‐Haul—options required to tackle the future challenges imposed by 5G radio access technologies. 5G‐XHaul studies the trade‐offs involving fully or partially converged backhaul and fronthaul functions, with the aim of maximising the associated sharing benefits, improving efficiency in resource utilisation and providing measurable benefits in terms of overall cost, scalability and sustainability. Copyright © 2016 John Wiley & Sons, Ltd.

Flow Scheduling in OBS Networks Based on Software-Defined Networking Control Plane

The separated management and operation of commercial IP/optical multilayer networks makes network operators look for a unified control plane (UCP) to reduce their capital and operational expenditure. Software-defined networking (SDN) provides a central control plane with a programmable mechanism, regarded as a promising UCP for future optical networks. The general control and scheduling mechanism in SDN-based optical burst switching (OBS) networks is insufficient so the controller has to process a large number of messages per second, resulting in low network resource utilization. In view of this, this paper presents the burst-flow scheduling mechanism (BFSM) with a proposed scheduling algorithm considering channel usage. The simulation results show that, compared with the general control and scheduling mechanism, BFSM provides higher resource utilization and controller performance for the SDN-based OBS network in terms of burst loss rate, the number of messages to which the controller responds, and the average latency of the controller to process a message.

An Overview of Optical Control Plane and Novel Unified Control Plane Architecture for IP/WDM Networks

An Overview of Optical Control Plane and Novel Unified Control Plane Architecture for IP/WDM Networks

OpenFlow and GMPLS Unified Control Planes: Testbed Implementation and Comparative Study

Finding an effective and simple unified control plane (UCP) for IP/dense wavelength division multiplexing multilayer optical networks is very important for network providers. Generalized multi-protocol label switching (GMPLS) has been in development for decades to control optical transport networks. However, it is extremely difficult to deploy in real operational products, as there is still much non-GMPLS-capable equipment. On the other hand, OpenFlow (OF), one of the most widely used software defined networking implementations, can be used as a UCP for packet and circuit switched networks [“Packet and circuit network convergence with OpenFlow,” in OFC/NFOEC, Mar. 2010]. In this paper, we propose and experimentally evaluate two solutions using OF to control both packet and optical networks (OpenFlow Messages Mapping and OpenFlow Extension). The overall feasibility of these solutions is assessed, and their performance is evaluated and compared with the GMPLS approach, using a custom-built simulator. Simulation results show that the OpenFlow Extension solution outperforms the OpenFlow Messages Mapping and GMPLS solutions.

Unified control plane: converged policy and charging control

This article describes a standardized architectural framework that enables network resources and policy control, and charging enforcement for both mobile and fixed networks. These capabilities together facilitate the realization of a unified control plane. The most relevant use cases supported by such a unified control plane are presented and described.

Adaptive Resource Management and Control in Software Defined Networks

The heterogeneous nature of the applications, technologies and equipment that today's networks have to support has made the management of such infrastructures a complex task. The Software-Defined Networking (SDN) paradigm has emerged as a promising solution to reduce this complexity through the creation of a unified control plane independent of specific vendor equipment. However, designing a SDN-based solution for network resource management raises several challenges as it should exhibit flexibility, scalability and adaptability. In this paper, we present a new SDN-based management and control framework for fixed backbone networks, which provides support for both static and dynamic resource management applications. The framework consists of three layers which interact with each other through a set of interfaces. We develop a placement algorithm to determine the allocation of managers and controllers in the proposed distributed management and control layer. We then show how this layer can satisfy the requirements of two specific applications for adaptive load-balancing and energy management purposes.

Software Defined Synergistic IP+Optical Resilient Transport Networks [Invited

Integrated orchestration of the IP+optical transport network has been well studied in recent years and has become a realistic trend in telecommunication network deployments. OpenFlow-based software defined network architecture is among the emerging and intensively investigated unified control plane solutions. Numerous previous works have focused on enabling optical networks to support the OpenFlow control plane, but mostly discussed from the single controller’s point of view. In real operational scenarios, however, there may inevitably exist different operators in different network layers/domains, and it is too idealized to have only one controller that is responsible for all devices. In light of this, here we propose and demonstrate an enhanced control plane architecture with hierarchically fabricated OpenFlow controllers. We specify the interworking relationships between different controllers on both IP and optical layers, and by using an IP+optical cross-layer information model, we show the effectiveness of unified routing and scheduling in terms of reducing the service blocking rate. Finally, dynamic cross-layer traffic adjustment and restoration are also successfully demonstrated on our implemented synergistic IP+optical network testbed with coordinated controllers.

On methodologies to estimate optical-layer power consumption and cost for long-haul WDM networks with optical reach constraint

This paper deals with the methodologies to obtain the estimates of optical-layer power consumption and cost for long-haul optical networks using wavelength-division multiplexing (WDM) with IP-over-WDM and IP-over-MPLS-over-WDM network settings. Such optical networks generally employ wavelength routing at intermediate nodes and are known as wavelength-routed optical networks (WRONs). In WRON-based long-haul networks, optical reach (OR) of a transponder represents the maximum distance over which its optical signal can travel without any optical/electrical/optical regeneration and plays a significant role in deciding the power consumption and cost of the optical layer. In IP-over-WDM network setting, IP routers are directly interfaced with WRON and bandwidth requests are equal to the lightpath capacity. In IP-over-MPLS-over-WDM network setting, IP routers are interfaced with WRON via MPLS routers and bandwidth requests arrive as label-switched paths, which are generally lower than the lightpath capacity. We examine the above networks with mixed-OR nodes (transponders in each WRON node having different OR values but all transmitting at 10 Gbps) and fixed-OR nodes (transponders in each WRON node having same OR value and 10 Gbps transmission rate). In this investigation, two types of control planes are considered, namely unified control plane and isolated control plane. The network with unified control plane supports automated and dynamic resource provisioning for both short-term and long-term bandwidth requests. The study on nonautomated network using isolated control plane considers resource provisioning only for long-term bandwidth requests. Simulation-based network provisioning is carried out using C++, considering appropriate traffic models, OR constraints, node configurations and network architectures. The results of our simulations indicate in general how OR of the transponders can influence the total network cost and power consumption in optical layer. Overall, the nonautomated networks with mixed-OR configuration are found to save power and offer lower cost with respect to fixed-OR configuration, while the automated networks with mixed-OR configuration can save power while the cost increases with respect to fixed-OR option.

Software-defined optical networks (SDONs): a survey

This paper gives an overview of software-defined optical networks (SDONs). It explains the general concepts on software-defined networks (SDNs), their relationship with network function virtualization, and also about OpenFlow, which is a pioneer protocol for SDNs. It then explains the benefits and challenges of extending SDNs to multilayer optical networks, including flexible grid and elastic optical networks, and how it compares to generalized multi-protocol label switching for implementing a unified control plane. An overview on the industry and research efforts on SDON standardization and implementation is given next, to bring the reader up to speed with the current state of the art in this field. Finally, the paper outlines the benefits achieved by SDONs for network operators, and also some of the important and relevant research problems that need to be addressed.

All-optical packet/circuit switching-based data center network for enhanced scalability, latency, and throughput

Applications running inside data centers are enabled through the cooperation of thousands of servers arranged in racks and interconnected together through the data center network. Current DCN architectures based on electronic devices are neither scalable to face the massive growth of DCs, nor flexible enough to efficiently and cost-effectively support highly dynamic application traffic profiles. The FP7 European Project LIGHTNESS foresees extending the capabilities of today's electrical DCNs through the introduction of optical packet switching and optical circuit switching paradigms, realizing together an advanced and highly scalable DCN architecture for ultra-high-bandwidth and low-latency server-to-server interconnection. This article reviews the current DC and high-performance computing (HPC) outlooks, followed by an analysis of the main requirements for future DCs and HPC platforms. As the key contribution of the article, the LIGHTNESS DCN solution is presented, deeply elaborating on the envisioned DCN data plane technologies, as well as on the unified SDN-enabled control plane architectural solution that will empower OPS and OCS transmission technologies with superior flexibility, manageability, and customizability.

Software-Defined Optical Networks Technology and Infrastructure: Enabling Software-Defined Optical Network Operations [Invited

Software-defined networking (SDN) enables programmable SDN control and management functions at a number of layers, allowing applications to control network resources or information across different technology domains, e.g., Ethernet, wireless, and optical. Current cloud-based services are pushing networks to new boundaries by deploying cutting edge optical technologies to provide scalable and flexible services. SDN combined with the latest optical transport technologies, such as elastic optical networks, enables network operators and cloud service providers to customize their infrastructure dynamically to user/application requirements and therefore minimize the extra capital and operational costs required for hosting new services. In this paper a unified control plane architecture based on OpenFlow for optical SDN tailored to cloud services is introduced. Requirements for its implementation are discussed considering emerging optical transport technologies. Implementations of the architecture are proposed and demonstrated across heterogeneous state-of-the-art optical, packet, and IT resource integrated cloud infrastructure. Finally, its performance is evaluated using cloud use cases and its results are discussed.

Experimental demonstration of an OpenFlow based software-defined optical network employing packet, fixed and flexible DWDM grid technologies on an international multi-domain testbed

Software defined networking (SDN) and flexible grid optical transport technology are two key technologies that allow network operators to customize their infrastructure based on application requirements and therefore minimizing the extra capital and operational costs required for hosting new applications. In this paper, for the first time we report on design, implementation & demonstration of a novel OpenFlow based SDN unified control plane allowing seamless operation across heterogeneous state-of-the-art optical and packet transport domains. We verify and experimentally evaluate OpenFlow protocol extensions for flexible DWDM grid transport technology along with its integration with fixed DWDM grid and layer-2 packet switching.