Software Defined Networking Orchestration Research Articles

Automated Network Services for Exascale Data Movement

The Large Hadron Collider (LHC) experiments distribute data by leveraging a diverse array of National Research and Education Networks (NRENs), where experiment data management systems treat networks as a “blackbox” resource. After the High Luminosity upgrade, the Compact Muon Solenoid (CMS) experiment alone will produce roughly 0.5 exabytes of data per year. NREN Networks are a critical part of the success of CMS and other LHC experiments. However, during data movement, NRENs are unaware of data priorities, importance, or need for quality of service, and this poses a challenge for operators to coordinate the movement of data and have predictable data flows across multi-domain networks. The overarching goal of SENSE (The Software-defined network for End-to-end Networked Science at Exascale) is to enable National Labs and universities to request and provision end-to-end intelligent network services for their application workflows leveraging SDN (Software-Defined Networking) capabilities. This work aims to allow LHC Experiments and Rucio, the data management software used by CMS Experiment, to allocate and prioritize certain data transfers over the wide area network. In this paper, we will present the current progress of the integration of SENSE, Multi-domain end-to-end SDN Orchestration with QoS (Quality of Service) capabilities, with Rucio, the data management software used by CMS Experiment.

Software-Defined Networking Orchestration for Interoperable Key Management of Quantum Key Distribution Networks.

This paper demonstrates the use of software-defined networking (SDN) orchestration to integrate regionally separated networks in which different network parts use incompatible key management systems (KMSs) managed by different SDN controllers to ensure end-to-end QKD service provisioning to deliver the QKD keys between geographically different QKD networks. The study focuses on scenarios in which different parts of the network are managed separately by different SDN controllers, requiring an SDN orchestrator to coordinate and manage these controllers. In practical network deployments, operators often utilize multiple vendors for their network equipment. This practice also enables the expansion of the QKD network's coverage by interconnecting various QKD networks equipped with devices from different vendors. However, as coordinating different parts of the QKD network is a complex task, this paper proposes the implementation of an SDN orchestrator which acts as a central entity to manage multiple SDN controllers, ensuring end-to-end QKD service provisioning to address this challenge. For instance, when there are multiple border nodes to interconnect different networks, the SDN orchestrator calculates the path in advance for the end-to-end delivery of keys between initiating and target applications belonging to different networks. This path selection requires the SDN orchestrator to gather information from each SDN controller managing the respective parts of the QKD network. This work shows the practical implementation of SDN orchestration for interoperable KMS in commercial QKD networks in South Korea. By employing an SDN orchestrator, it becomes possible to coordinate multiple SDN controllers and ensure the efficient and secure delivery of QKD keys between different QKD networks with varying vendor equipment.

ARES: A Framework for Management of Aging and Rejuvenation in Softwarized Networks

The recent trend of network softwarization suggests a radical shift in the implementation of traditional network intelligence. In Software Defined Networking (SDN), for instance, the control plane functions of forwarding devices are outsourced to the controller. Softwarized network components are expected to provide uninterrupted service during long periods of time, which makes them prone to the effects of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">software aging</i> , a phenomena that has been observed in operational software systems where the failure rate increases or the performance of the software degrades with the elapsed time since the last restart. The effects of software aging in operational networks are typically mitigated by <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">software rejuvenation</i> , i.e., planned restarts cleaning the internal system state in order to prevent or postpone aging-related failures. This article presents <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ARES</i> , a three-step methodological framework for the management of the effects of software aging in softwarized networks, applied to the case study of open source SDN orchestration platforms. Using ARES, we demonstrate that software aging is a systematic problem that cannot be neglected in network orchestration systems. It stems not only from aging-related bugs and natural aging due to fragmentation, but also from design choices, e.g., when implementing distributed systems. Measurements for Open Network Operating System (ONOS) and OpenDaylight (ODL) demonstrate how “simple” and common networking tasks let network performance degrade rapidly and even lead to crashes: for instance, adding and removing 300 intents per second in ONOS significantly increases the response time by 50% per day and depletes the memory at the rate of 18GB per day. Moreover, we demonstrate a first rejuvenation approach that can mitigate the effects of aging in ONOS.

5G network slicing with QKD and quantum-safe security

We demonstrate how the 5G network slicing model can be enhanced to address data security requirements. In this work, we demonstrate two different slice configurations, with different encryption requirements, representing two diverse use-cases for 5G networking, namely, an enterprise application hosted at a metro network site and a content delivery network. We create a modified software-defined networking (SDN) orchestrator that calculates and provisions network slices according to the requirements, including encryption backed by quantum key distribution (QKD) and other methods. Slices are automatically provisioned by SDN orchestration of network resources, allowing selection of encrypted links as appropriate, including those that use encryption with standard Diffie–Hellman key exchange, QKD, or quantum-resistant algorithms, as well as no encryption at all. We show that the setup and teardown times of the network slices take approximately 1–2 min, which is at least an order of magnitude improvement over manually provisioning a link today.

Aloe: Fault-Tolerant Network Management and Orchestration Framework for IoT Applications

Internet of Things (IoT) platforms use a large number of low-cost resource constrained devices and generates millions of short-flows. In-network processing is gaining popularity day by day to handle IoT applications and services. However, traditional software-defined networking (SDN) based management systems are not suitable to handle the plug and play nature of such systems. In this paper, we propose Aloe, an auto-scalable SDN orchestration framework. Aloe exploits in-network processing framework by using multiple lightweight controller instances in place of service grade SDN controller applications. The proposed framework ensures the availability and significant reduction in flow-setup delay by deploying instances in the vicinity the resource constraint IoT devices dynamically. Aloe supports fault-tolerance with recovery from network partitioning by employing self-stabilizing placement of migration capable controller instances. Aloe also provides resource reservation for micro-controllers so that they can ensure the quality of services (QoS). The performance of the proposed system is measured by using an in-house testbed along with a large scale deployment in Amazon Web services (AWS) cloud platform. The experimental results from these two testbeds show significant improvement in response time for standard IoT based services. This improvement of performance is due to the reduction in flow-setup time. We found that Aloe can improve flow-setup time by around 10%-30% in comparison to one of the states of the art orchestration framework.

Experimenting SDN and Cloud Orchestration in Virtualized Testing Facilities: Performance Results and Comparison

Due to the impressive demand for communication-intensive applications deployed in the cloud, cross-layer orchestration solutions for Cloud data centers (DCs) are essential for the effective usage of both network and cloud resources while addressing service requirements and user expectations. In this regard, the software-defined networking (SDN) can play a key role thanks to programmable network control operations and to a more effective inter-working between network controllers and cloud management platforms. On the other hand, due to the relevant size of Cloud DCs, a significant evaluation of SDN-based orchestration solutions requires testing environments with proper scales, and significant level of fidelity. This paper discusses the opportunities of using virtual testbeds to carry out Cloud-related experimentations while addressing with significant scale requirements of DC infrastructures. First, we present a set of results of a test campaign we carried out using the Fed4FIRE experimental facility aiming at a comprehensive performance evaluation of an SDN-based orchestration solution for Cloud DCs. Second, we provide a comparison between virtual testbeds and other testing environments, i.e., laboratory testbeds, simulators and emulators, in terms of offered advantages, and effectiveness in experimentations. Moreover, we discuss the appropriateness and advisability of using virtualized testbeds for research on novel SDN and Cloud orchestration solutions at scale, by highlighting advantages of virtual testbeds in comparison with laboratory, simulation and emulation testing facilities in terms of effectiveness of experimentations and accuracy of results.

Centralized vs. distributed algorithms for resilient 5G access networks

Cloud radio access networks (C-RANs), relying on network function virtualization and software-defined networking (SDN), require a proper placement of baseband functionalities (BBUs) to reach full coverage of served areas and service continuity. In this context, network resources can be shared and orchestrated to meet the flexibility required by a dynamically evolving environment. Different methodologies, based on analytical formulation or heuristic algorithms, can be applied to achieve suitable trade-offs among cost components. This paper considers both centralized and distributed algorithms to obtain BBU hotel placement in C-RAN and compares their performance, scalability and adaptability to evolving scenarios. As expected, the results obtained with the distributed approach are sub-optimal, but very close, in most cases, to the optimal solutions obtained with a centralized algorithm based on integer linear programming. In addition to off-loading the SDN orchestrator, the distributed approach, differently from the centralized one, is shown to be able to cope with the evolution of the C-RAN topology with limited incremental changes in the original placement. The limits of the centralized approach in terms of scalability that the distributed approach is able to overcome are also evidenced.

A Dynamic Multi-Layer Resource Allocation and Optimization Framework in Application-Centric Networks

In a software-defined networking (SDN) based network, service requests can be accommodated according to the network application requirements. We devise a framework where such requirements drive IP and optical network resource allocation, dynamic optimization, and instantiation through an SDN orchestrator. The framework aims to balance the often-conflicting goals such as energy savings and resource allocation speed, while ensuring that the orchestrator can accommodate incoming service requests without interrupting the running services. We show the functionality of the framework with a simulation on a real network topology and a realistic input traffic.

Inter-Domain Optimization and Orchestration for Optical Datacenter Networks

Hyperscale datacenters (DCs), spread in various locations around the globe, provide computing and storage resources for cloud and other applications. Elastic optical networks (both landline and subsea) operated by a single or multiple entities are used to form the inter-DC network and serve the constantly increasing traffic. In addition, optical switching technologies are researched for intra-DC networks as a means to achieve higher capacity and energy efficiency. Joint optimization and orchestration of inter-DC and intra-DC network infrastructures is the key for realizing the network virtualization and network as service visions. We present a hierarchical software defined networking orchestration platform that treats intra-DC and inter-DC networks as domains and cooperates with domain specific orchestrators/controllers to achieve interdomain, end-to-end orchestration. The systems developed are evaluated both in an emulated and in a realistic testbed, showcasing dynamic end-to-end path establishment functionality with dedicated capacity and low control overhead.

LayBack: SDN Management of Multi-Access Edge Computing (MEC) for Network Access Services and Radio Resource Sharing

Existing radio access networks (RANs) allow only for very limited sharing of the communication and computation resources among wireless operators and heterogeneous wireless technologies. We introduce the LayBack architecture to facilitate communication and computation resource sharing among different wireless operators and technologies. LayBack organizes the RAN communication and multiaccess edge computing (MEC) resources into layers, including a devices layer, a radio node (enhanced Node B and access point) layer, and a gateway layer. LayBack positions the coordination point between the different operators and technologies just behind the gateways and thus consistently decouples the fronthaul from the backhaul. The coordination point is implemented through a software defined networking (SDN) switching layer that connects the gateways to the backhaul (core) network layer. A unifying SDN orchestrator implements an SDN-based management framework that centrally manages the fronthaul and backhaul communication and computation resources and coordinates the cooperation between different wireless operators and technologies. We illustrate the capabilities of the introduced LayBack architecture and SDN-based management framework through a case study on a novel fluid cloud RAN (CRAN) function split. The fluid CRAN function split partitions the RAN functions into function blocks that are flexibly assigned to MEC nodes, effectively implementing the RAN functions through network function virtualization. We find that for non-uniform call arrivals, the computation of the function blocks with resource sharing among operators increases a revenue rate measure by more than 25% compared to the conventional CRAN where each operator utilizes only its own resources.

De-optical-line-terminal hybrid access–aggregation optical network for time-sensitive services based on software-defined networking orchestration

With the increase in varieties of services in network, time-sensitive services (TSSs) appear and bring forward an impending need for delay performance. Ultralow-latency communication has become one of the important development goals for many scenarios in the coming 5G era (e.g., robotics and driverless cars). However, the conventional methods, which decrease delay by promoting the available resources and the network transmission speed, have limited effect; a new breakthrough for ultralow-latency communication is necessary. We propose a de-optical-line-terminal (De-OLT) hybrid access–aggregation optical network (DAON) for TSS based on software-defined networking (SDN) orchestration. In this network, low-latency all-optical communication based on optical burst switching can be achieved by removing OLT. For supporting this network and guaranteeing the quality of service for TSSs, we design SDN-driven control method and service provision method. Numerical results demonstrate the proposed DAON promotes network service efficiency and avoids traffic congestion.

Demonstration of Adaptive SDN Orchestration: A Real-Time Congestion-Aware Services Provisioning Over OFDM-Based 400G OPS and Flexi-WDM OCS

In this Paper, we experimentally demonstrate highly flexible and intelligent interdomain coordinated actions based on adaptive software-defined networking (SDN) orchestration. An advanced multidomain multitechnology testbed is implemented, which consists of a 400-Gb/s variable capacity optical packet switching domain and a Tb/s-class flexi-grid wavelength division multiplexed optical circuit switching domain. The SDN-controllable transponders and the extended transport applications programming interface enable the congestion-aware provisioning of end-to-end real-time services. At the data plane level, different transponders based on orthogonal frequency division multiplexing are employed for inter/intradomain links in order to adaptively provision services with fine granularity. For adaptation, SDN-capable domain-specific optical performance monitors are also introduced. In the control plane, the applications based network operations architecture has been extended and addressed as an adaptive SDN orchestrator.

SDN-Based Smart Gateways (Sm-GWs) for Multi-Operator Small Cell Network Management

Small wireless cells have the potential to overcome bottlenecks in wireless access through the sharing of spectrum resources. However, current backhaul networks statically allocate resources, resulting in minuscule allocations when many small cells are connected to cellular operators with given resources. We introduce a novel access backhaul network architecture based on a smart gateway (Sm-GW) between the small cell base stations, e.g., long term evolution (LTE) enhanced Nodes B (eNBs), and the conventional backhaul gateways, e.g., LTE servicing/packet gateways (S/P-GWs). We specify the modest LTE protocol modifications that integrate the Sm-GW into the conventional LTE network. The Sm-GW flexibly schedules uplink transmissions for the eNBs. Our simulation evaluations indicate that the Sm-GW scheduling can fairly allocate uplink transmission bitrates to the eNBs and reduce packet delays. Based on software defined networking (SDN), we introduce a management mechanism that allows multiple operators, i.e., multiple S/P-GWs, to flexibly inter-operate via multiple Sm-GWs with a multitude of small cells. An SDN orchestrator coordinates the adaptive allocation of uplink transmission bitrates to Sm-GWs (which in turn allocate the uplink transmission bitrates to eNBs based on their demands). We formulate optimization problems for the operator (S/P-GW) resource allocation to Sm-GWs without and with sharing among operators. Our numerical evaluations indicate that the flexible SDN orchestration substantially increases the network throughput compared to the current static resource allocations.

SDN orchestration architectures and their integration with Cloud Computing applications

Emerging cloud-based applications, running in geographically distributed data centers (DCs), generate new dynamic traffic patterns which claim for a more efficient management of the traffic flows. Geographically distributed DCs interconnection requires automatic and more dynamic provisioning and deletion of end-to-end (E2E) connectivity services, through heterogeneous network domains. Each network domain may use a different data transport technology but also a different control/management system. The fast development of Software Defined Networking (SDN) and the interworking with current control plane technologies such as Generalized Multi-protocol Label Switching (GMPLS), demand orchestration over the heterogeneous control instances to provide seamless E2E connectivity services to external applications (i.e. Cloud Computing applications).In this work, we present different orchestration architectures based on the SDN principles which use the Path Computation Element (PCE) as a fundamental component. In particular, a single SDN controller orchestration approach is compared with an orchestration architecture based on the Application Based Network Operations (ABNO) defined within the International Engineering Task Force (IETF), in order to find the potential benefits and drawbacks of both architectures. Finally, the SDN IT and Network Orchestration (SINO) platform which integrates the management of Cloud Computing infrastructure with the network orchestration, it is used to validate both architectures by evaluating their performance providing two inter-DC connectivity services: E2E connectivity and Virtual Machine (VM) migration.

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/ OpenFlow domains or multiple OpenFlow/ Generalized Multi-Protocol Label Switching (GMPLS) heterogeneous domains. In addition, two concrete implementations of the orchestration architectures are detailed, showing the overall feasibility and procedures of SDN orchestration for the end-to-end service provisioning in multi-domain data center optical networks.

SDN Orchestration of OpenFlow and GMPLS Flexi-Grid Networks With a Stateful Hierarchical PCE [Invited

New and emerging use cases, such as the interconnection of geographically remote data centers, are drawing attention to the need for provisioning end-to-end connectivity services spanning multiple and heterogeneous network domains. This heterogeneity is due not only to the data transmission and switching technology (the so-called data plane) but also to the deployed control plane, which may be used within each domain to automate the setup and recovery of such services, dynamically. The choice of a control plane is affected by factors such as availability, maturity, operator&#x2019;s preference, and the ability to satisfy a list of functional requirements. Given the current developments around OpenFlow and software-defined networking (SDN) along with the need to account for existing deployments based on GMPLS, the problem of heterogeneous control plane interworking needs to be solved. The retained solution must equally address the specific issues of multidomain networks, such as limited domain topology visibility, given the scalability and confidentiality constraints that characterize them. In this setting, we propose a functional and protocol architecture for such interworking, based on the key concepts of network abstraction and overarching control, implemented in terms of a hierarchical stateful path computation element (PCE), which provides the orchestration and coordination layer. In the proposed architecture, the PCEP and BGP-LS protocols are extended to support OpenFlow addresses and datapath identifiers, unifying both GMPLS and OpenFlow domains. The solution is deployed in an experimental testbed and validated. Although the main scope of the approach is the interworking of OpenFlow and GMPLS, the same approach can be directly applied to a wide range of multidomain scenarios, with either homogeneous or heterogeneous control technologies.