307 research outputs found
Progressive introduction of network softwarization in operational telecom networks: advances at architectural, service and transport levels
Technological paradigms such as Software Defined Networking, Network Function
Virtualization and Network Slicing are altogether offering new ways of providing services.
This process is widely known as Network Softwarization, where traditional operational
networks adopt capabilities and mechanisms inherit form the computing world, such as
programmability, virtualization and multi-tenancy.
This adoption brings a number of challenges, both from the technological and operational
perspectives. On the other hand, they provide an unprecedented flexibility opening
opportunities to developing new services and new ways of exploiting and consuming telecom
networks.
This Thesis first overviews the implications of the progressive introduction of network
softwarization in operational networks for later on detail some advances at different levels,
namely architectural, service and transport levels. It is done through specific exemplary use
cases and evolution scenarios, with the goal of illustrating both new possibilities and existing
gaps for the ongoing transition towards an advanced future mode of operation.
This is performed from the perspective of a telecom operator, paying special attention on
how to integrate all these paradigms into operational networks for assisting on their evolution
targeting new, more sophisticated service demands.Programa de Doctorado en Ingeniería Telemática por la Universidad Carlos III de MadridPresidente: Eduardo Juan Jacob Taquet.- Secretario: Francisco Valera Pintor.- Vocal: Jorge López Vizcaín
Network Service Orchestration: A Survey
Business models of network service providers are undergoing an evolving
transformation fueled by vertical customer demands and technological advances
such as 5G, Software Defined Networking~(SDN), and Network Function
Virtualization~(NFV). Emerging scenarios call for agile network services
consuming network, storage, and compute resources across heterogeneous
infrastructures and administrative domains. Coordinating resource control and
service creation across interconnected domains and diverse technologies becomes
a grand challenge. Research and development efforts are being devoted to
enabling orchestration processes to automate, coordinate, and manage the
deployment and operation of network services. In this survey, we delve into the
topic of Network Service Orchestration~(NSO) by reviewing the historical
background, relevant research projects, enabling technologies, and
standardization activities. We define key concepts and propose a taxonomy of
NSO approaches and solutions to pave the way towards a common understanding of
the various ongoing efforts around the realization of diverse NSO application
scenarios. Based on the analysis of the state of affairs, we present a series
of open challenges and research opportunities, altogether contributing to a
timely and comprehensive survey on the vibrant and strategic topic of network
service orchestration.Comment: Accepted for publication at Computer Communications Journa
Next generation control of transport networks
It is widely understood by telecom operators and industry analysts that bandwidth demand is increasing dramatically, year on year, with typical growth figures of 50% for Internet-based traffic [5]. This trend means that the consumers will have both a wide variety of devices attaching to their networks and a range of high bandwidth service requirements. The corresponding impact is the effect on the traffic engineered network (often referred to as the “transport network”) to ensure that the current rate of growth of network traffic is supported and meets predicted future demands. As traffic demands increase and newer services continuously arise, novel network elements are needed to provide more flexibility, scalability, resilience, and adaptability to today’s transport network. The transport network provides transparent traffic engineered communication of user, application, and device traffic between attached clients (software and hardware) and establishing and maintaining point-to-point or point-to-multipoint connections. The research documented in this thesis was based on three initial research questions posed while performing research at British Telecom research labs and investigating control of transport networks of future transport networks: 1. How can we meet Internet bandwidth growth yet minimise network costs? 2. Which enabling network technologies might be leveraged to control network layers and functions cooperatively, instead of separated network layer and technology control? 3. Is it possible to utilise both centralised and distributed control mechanisms for automation and traffic optimisation? This thesis aims to provide the classification, motivation, invention, and evolution of a next generation control framework for transport networks, and special consideration of delivering broadcast video traffic to UK subscribers. The document outlines pertinent telecoms technology and current art, how requirements I gathered, and research I conducted, and by which the transport control framework functional components are identified and selected, and by which method the architecture was implemented and applied to key research projects requiring next generation control capabilities, both at British Telecom and the wider research community. Finally, in the closing chapters, the thesis outlines the next steps for ongoing research and development of the transport network framework and key areas for further study
Segment Routing: a Comprehensive Survey of Research Activities, Standardization Efforts and Implementation Results
Fixed and mobile telecom operators, enterprise network operators and cloud
providers strive to face the challenging demands coming from the evolution of
IP networks (e.g. huge bandwidth requirements, integration of billions of
devices and millions of services in the cloud). Proposed in the early 2010s,
Segment Routing (SR) architecture helps face these challenging demands, and it
is currently being adopted and deployed. SR architecture is based on the
concept of source routing and has interesting scalability properties, as it
dramatically reduces the amount of state information to be configured in the
core nodes to support complex services. SR architecture was first implemented
with the MPLS dataplane and then, quite recently, with the IPv6 dataplane
(SRv6). IPv6 SR architecture (SRv6) has been extended from the simple steering
of packets across nodes to a general network programming approach, making it
very suitable for use cases such as Service Function Chaining and Network
Function Virtualization. In this paper we present a tutorial and a
comprehensive survey on SR technology, analyzing standardization efforts,
patents, research activities and implementation results. We start with an
introduction on the motivations for Segment Routing and an overview of its
evolution and standardization. Then, we provide a tutorial on Segment Routing
technology, with a focus on the novel SRv6 solution. We discuss the
standardization efforts and the patents providing details on the most important
documents and mentioning other ongoing activities. We then thoroughly analyze
research activities according to a taxonomy. We have identified 8 main
categories during our analysis of the current state of play: Monitoring,
Traffic Engineering, Failure Recovery, Centrally Controlled Architectures, Path
Encoding, Network Programming, Performance Evaluation and Miscellaneous...Comment: SUBMITTED TO IEEE COMMUNICATIONS SURVEYS & TUTORIAL
5G Network Slicing using SDN and NFV: A Survey of Taxonomy, Architectures and Future Challenges
In this paper, we provide a comprehensive review and updated solutions
related to 5G network slicing using SDN and NFV. Firstly, we present 5G service
quality and business requirements followed by a description of 5G network
softwarization and slicing paradigms including essential concepts, history and
different use cases. Secondly, we provide a tutorial of 5G network slicing
technology enablers including SDN, NFV, MEC, cloud/Fog computing, network
hypervisors, virtual machines & containers. Thidly, we comprehensively survey
different industrial initiatives and projects that are pushing forward the
adoption of SDN and NFV in accelerating 5G network slicing. A comparison of
various 5G architectural approaches in terms of practical implementations,
technology adoptions and deployment strategies is presented. Moreover, we
provide a discussion on various open source orchestrators and proof of concepts
representing industrial contribution. The work also investigates the
standardization efforts in 5G networks regarding network slicing and
softwarization. Additionally, the article presents the management and
orchestration of network slices in a single domain followed by a comprehensive
survey of management and orchestration approaches in 5G network slicing across
multiple domains while supporting multiple tenants. Furthermore, we highlight
the future challenges and research directions regarding network softwarization
and slicing using SDN and NFV in 5G networks.Comment: 40 Pages, 22 figures, published in computer networks (Open Access
Resource orchestration strategies with retrials for latency-sensitive network slicing over distributed telco clouds
The new radio technologies (i.e. 5G and beyond) will allow a new generation of innovative services operated by vertical industries (e.g. robotic cloud, autonomous vehicles, etc.) with more stringent QoS requirements, especially in terms of end-to-end latency. Other technological changes, such as Network Function Virtualization (NFV) and Software-Defined Networking (SDN), will bring unique service capabilities to networks by enabling flexible network slicing that can be tailored to the needs of vertical services. However, effective orchestration strategies need to be put in place to offer latency minimization while also maximizing resource utilization for telco providers to address vertical requirements and increase their revenue. Looking at this objective, this paper addresses a latency-sensitive orchestration problem by proposing different strategies for the coordinated selection of virtual resources (network, computational, and storage resources) in distributed DCs while meeting vertical requirements (e.g., bandwidth demand) for network slicing. Three orchestration strategies are presented to minimize latency or the blocking probability through effective resource utilization. To further reduce the slice request blocking, orchestration strategies also encompass a retrial mechanism applied to rejected slice requests. Regarding latency, two components were considered, namely processing and network latency. An extensive set of simulations was carried out over a wide and composite telco cloud infrastructure in which different types of data centers coexist characterized by a different network location, size, and processing capacity. The results compare the behavior of the strategies in addressing latency minimization and service request fulfillment, also considering the impact of the retrial mechanism.This work was supported in part by the Department of Excellence in Robotics and Artificial Intelligence by Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR) to Scuola Superiore Sant’Anna, and in part by the Project 5GROWTH under Agreement 856709
The Four-C Framework for High Capacity Ultra-Low Latency in 5G Networks: A Review
Network latency will be a critical performance metric for the Fifth Generation (5G) networks
expected to be fully rolled out in 2020 through the IMT-2020 project. The multi-user multiple-input
multiple-output (MU-MIMO) technology is a key enabler for the 5G massive connectivity criterion,
especially from the massive densification perspective. Naturally, it appears that 5G MU-MIMO will
face a daunting task to achieve an end-to-end 1 ms ultra-low latency budget if traditional network
set-ups criteria are strictly adhered to. Moreover, 5G latency will have added dimensions of scalability
and flexibility compared to prior existing deployed technologies. The scalability dimension caters
for meeting rapid demand as new applications evolve. While flexibility complements the scalability
dimension by investigating novel non-stacked protocol architecture. The goal of this review paper
is to deploy ultra-low latency reduction framework for 5G communications considering flexibility
and scalability. The Four (4) C framework consisting of cost, complexity, cross-layer and computing
is hereby analyzed and discussed. The Four (4) C framework discusses several emerging new
technologies of software defined network (SDN), network function virtualization (NFV) and fog
networking. This review paper will contribute significantly towards the future implementation of
flexible and high capacity ultra-low latency 5G communications
- …