236 research outputs found

    Intelligent adaptive bandwidth provisioning for quality of service in umts core networks

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    Master'sMASTER OF ENGINEERIN

    Management of Carrier Grade Intra-Domain Ethernet

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    Internet ei ole enää pelkkä tiedonlähde, vaan enenevässä määrin kriittisempi osa yhteiskunnan infrastruktuuria. Nykyiset Internet-palveluja tuottavat teknologiat - IPv4 osoitteistuksessa, MPLS siirtoalustana ja SDH fyysisenä välitysteknologiana - ovat alkaneet menettää valta-asemaansa samalla kun kaikille tuttu verkkoteknologia, Ethernet, on laajentunut lähiverkoista runkoverkkoihin. Maailmassa on miljoonia Ethernet-lähiverkkoja. Olisi kustannustehokaampaa toteuttaa myös näiden lähiverkkojen väliset siirtoyhteydet Ethernetillä. Halu kustannustehokkuuteen ja teknologian konsolidointiin on tuonut esille tarpeen ns. operaattorikestoisille Ethernet-palveluille. Koska Ethernetistä puuttuu määrättyjä ominaisuuksia joita ilman on mahdotonta toteuttaa siirtoverkkopalveluja, näitä operaattori-Ethernet-palveluja on tuotettu toistaiseksi olemassa olevilla tekniikoilla, kuten MPLS:llä. Tulevaisuudessa todellinen haaste on luoda operaattoritasoinen, Ethernet-pohjainen siirtoverkkoteknologia, joka kykenee tuottamaan Ethernet-palvelujen lisäksi mitä tahansa muita tietoliikennepalveluja. Tämä diplomityö käsittelee operaattoritasoisen Ethernetin hallintaa yhden runkoverkkoalueen sisällä. Työssä käydään läpi standardoidut operaattorikestoiset Ethernet-palvelut, teknologiat joilla palveluja tällä hetkellä tuotetaan, ehdokkaat tulevaisuuden Ethernet-siirtoverkkoteknologioiksi sekä keskeisimmät verkonhallintaan liittyvät standardit. Työn jälkimmäisessä puoliskossa esitellään Euroopan Unionin 7th Framework ETNA -projektia varten kehitetty verkonhallintajärjestelmä. Hallintajärjestelmä tarjoaa rajapinnan jonka kautta on mahdollista provisioida suojattuja Ethernet-palveluja kahden asiakasliityntäpisteen välillä, ja lisäksi lähetyspuita joissa kohteina on useampi asiakaspiste. Hallintajärjestelmältä tilatut palvelut viestitetään Ben Gurionin yliopiston toteuttaman, verkkoprosessoreilla toimivan välityskerroksen välitystauluihin.Internet is evolving from its role as a mere information provider to an ubiquitous infrastructure crucial to society. The current technologies running the majority of global Internet - IPv4 in addressing, MPLS as core transport and SDH as the physical transfer technology - have been long-lived. However, their dominance has started to diminish because a network technology common to all, Ethernet, has started to expand from local to metropolitan and wide area networks. Most enterprises and home users already use Ethernet in their LAN. Connecting these sites to MAN or WAN with the same technology is the logical next step in technology consolidation. This has raised the demand for Carrier Ethernet services. However, internally they are still mostly provided with non-Ethernet technologies such as MPLS or SDH, because currently Ethernet lacks the necessary service assurance components. The real challenge in future internetworking is creating a Carrier Ethernet Transport (CET). With CET, any imaginable telecommunication service is delivered with a purely Ethernet based technology. When we have Ethernet in transport networks, it is no more a long stretch to a global, routed end-to-end Ethernet. This thesis covers management of an intra-domain CET control plane. First, Carrier Ethernet services and technologies currently producing these services are analyzed. Second, requirements imposed to CET and current CET candidates are discussed. Third, network management standards and their alignment to carrier business is studied. After the background has been discussed, a control plane management system developed for the EU 7th framework ETNA project is introduced. The management system is capable of provisioning point-to-point and multipoint services and is controlled via a web-service -based northbound interface. The control plane is able to install the services as forwarding entries in a network processor -driven data plane developed at Ben Gurion University

    Deployment and validation of a communication suite using an NFV service platform

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    Telecommunications are in permanent and constant change. The arrival of 5G brings new use cases to the table, wich drive the standarisation and where the efforts shall be directed. Also, Vertical Industries are demanding better performance in terms of network flexibility and computation power to Infrastructure Providers, and even vertical applications are requiring more complex scenarios (e.g., in Industrial, Immersive Media and Real Time Communication applications). Vertical industries do not only require a reliable, fast platform, but also to reduce on time-to-market and capability to manage Quality of Service (QoS) for certain applications. ETSI Network Functions Virtualisation (NFV) ISG is doing an effort to give solutions to these new problems aroused. In NFV nomenclature, these applications are abstracted by a concept called Network Service. Some of these Network Services might be instantiated in complex scenarios, which must be connected across a Wide Area Networks (WAN), where recently Software Defined Networks (SDN) have been acquiring more importance, reducing Capex and Opex costs for WAN providers but also speeding up the process of network configuration, where Open and well-defined APIs are becoming a key to success. To solve the problem of instantiating services across a WAN, there exist the concept of WAN Infrastructure Manager (WIM), a component defined in ETSI NFV architecture and which currently Orchestration Platforms developers are bringing up some solutions with. WIM(s) communicates directly with the NFV Orchestrator, the main component governing a NFV Management and Orchestration Platform. In this respect, this thesis has developed a solution within 5GPPP 5GTANGO project to extend SONATA NFV platform in order to be used to deploy network services over multiple Virtualisation Infrastructure Managers (VIM), which are interconnected through one or multiple WIM(s), using ONF Transport API (T-API) definition as WIM Southbound API Interface. Moreover, these instantiation has been validated and it has been analyzed the benefit of using a Point Of Presence (PoP) closer located at the 'edge' for instantiating a QoS reliant Network Service. T-API has been also extended in order to be used in application connectivity services, allowing an extension of what is called in SDN 'flow matching'. Thus, the main output of this thesis is going to be included in new SONATA Service Platform release 5.0, and furthermore is going to have a critical importance to give functionality to one of 5GTANGO project pilots

    Network Infrastructures for Highly Distributed Cloud-Computing

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    Software-Defined-Network (SDN) is emerging as a solid opportunity for the Network Service Providers (NSP) to reduce costs while at the same time providing better and/or new services. The possibility to flexibly manage and configure highly-available and scalable network services through data model abstractions and easy-to-consume APIs is attractive and the adoption of such technologies is gaining momentum. At the same time, NSPs are planning to innovate their infrastructures through a process of network softwarisation and programmability. The SDN paradigm aims at improving the design, configuration, maintenance and service provisioning agility of the network through a centralised software control. This can be easily achievable in local area networks, typical of data-centers, where the benefits of having programmable access to the entire network is not restricted by latency between the network devices and the SDN controller which is reasonably located in the same LAN of the data path nodes. In Wide Area Networks (WAN), instead, a centralised control plane limits the speed of responsiveness in reaction to time-constrained network events due to unavoidable latencies caused by physical distances. Moreover, an end-to-end control shall involve the participation of multiple, domain-specific, controllers: access devices, data-center fabrics and backbone networks have very different characteristics and their control-plane could hardly coexist in a single centralised entity, unless of very complex solutions which inevitably lead to software bugs, inconsistent states and performance issues. In recent years, the idea to exploit SDN for WAN infrastructures to connect multiple sites together has spread in both the scientific community and the industry. The former has produced interesting results in terms of framework proposals, complexity and performance analysis for network resource allocation schemes and open-source proof of concept prototypes targeting SDN architectures spanning multiple technological and administrative domains. On the other hand, much of the work still remains confined to the academy mainly because based on pure Openflow prototype implementation, networks emulated on a single general-purpose machine or on simulations proving algorithms effectiveness. The industry has made SDN a reality via closed-source systems, running on single administrative domain networks with little if no diversification of access and backbone devices. In this dissertation we present our contributions to the design and the implementation of SDN architectures for the control plane of WAN infrastructures. In particular, we studied and prototyped two SDN platforms to build a programmable, intent-based, control-plane suitable for the today highly distributed cloud infrastructures. Our main contributions are: (i) an holistic and architectural description of a distributed SDN control-plane for end-end QoS provisioning; we compare the legacy IntServ RSVP protocol with a novel approach for prioritising application-sensitive flows via centralised vantage points. It is based on a peer-to-peer architecture and could so be suitable for the inter-authoritative domains scenario. (ii) An open-source platform based on a two-layer hierarchy of network controllers designed to provision end-to-end connectivity in real networks composed by heterogeneous devices and links within a single authoritative domain. This platform has been integrated in CORD, an open-source project whose goal is to bring data-center economics and cloud agility to the NSP central office infrastructures, combining NFV (Network Function Virtualization), SDN and the elasticity of commodity clouds. Our platform enables the provisioning of connectivity services between multiple CORD sites, up to the customer premises. Thus our system and software contributions in SDN has been combined with a NFV infrastructure for network service automation and orchestration

    Progressive introduction of network softwarization in operational telecom networks: advances at architectural, service and transport levels

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    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

    Quality aspects of Internet telephony

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    Internet telephony has had a tremendous impact on how people communicate. Many now maintain contact using some form of Internet telephony. Therefore the motivation for this work has been to address the quality aspects of real-world Internet telephony for both fixed and wireless telecommunication. The focus has been on the quality aspects of voice communication, since poor quality leads often to user dissatisfaction. The scope of the work has been broad in order to address the main factors within IP-based voice communication. The first four chapters of this dissertation constitute the background material. The first chapter outlines where Internet telephony is deployed today. It also motivates the topics and techniques used in this research. The second chapter provides the background on Internet telephony including signalling, speech coding and voice Internetworking. The third chapter focuses solely on quality measures for packetised voice systems and finally the fourth chapter is devoted to the history of voice research. The appendix of this dissertation constitutes the research contributions. It includes an examination of the access network, focusing on how calls are multiplexed in wired and wireless systems. Subsequently in the wireless case, we consider how to handover calls from 802.11 networks to the cellular infrastructure. We then consider the Internet backbone where most of our work is devoted to measurements specifically for Internet telephony. The applications of these measurements have been estimating telephony arrival processes, measuring call quality, and quantifying the trend in Internet telephony quality over several years. We also consider the end systems, since they are responsible for reconstructing a voice stream given loss and delay constraints. Finally we estimate voice quality using the ITU proposal PESQ and the packet loss process. The main contribution of this work is a systematic examination of Internet telephony. We describe several methods to enable adaptable solutions for maintaining consistent voice quality. We have also found that relatively small technical changes can lead to substantial user quality improvements. A second contribution of this work is a suite of software tools designed to ascertain voice quality in IP networks. Some of these tools are in use within commercial systems today

    QoS Provisioning in Converged Satellite and Terrestrial Networks: A Survey of the State-of-the-Art

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    It has been widely acknowledged that future networks will need to provide significantly more capacity than current ones in order to deal with the increasing traffic demands of the users. Particularly in regions where optical fibers are unlikely to be deployed due to economical constraints, this is a major challenge. One option to address this issue is to complement existing narrow-band terrestrial networks with additional satellite connections. Satellites cover huge areas, and recent developments have considerably increased the available capacity while decreasing the cost. However, geostationary satellite links have significantly different link characteristics than most terrestrial links, mainly due to the higher signal propagation time, which often renders them not suitable for delay intolerant traffic. This paper surveys the current state-of-the-art of satellite and terrestrial network convergence. We mainly focus on scenarios in which satellite networks complement existing terrestrial infrastructures, i.e., parallel satellite and terrestrial links exist, in order to provide high bandwidth connections while ideally achieving a similar end user quality-of-experience as in high bandwidth terrestrial networks. Thus, we identify the technical challenges associated with the convergence of satellite and terrestrial networks and analyze the related work. Based on this, we identify four key functional building blocks, which are essential to distribute traffic optimally between the terrestrial and the satellite networks. These are the traffic requirement identification function, the link characteristics identification function, as well as the traffic engineering function and the execution function. Afterwards, we survey current network architectures with respect to these key functional building blocks and perform a gap analysis, which shows that all analyzed network architectures require adaptations to effectively support converged satellite and terrestrial networks. Hence, we conclude by formulating several open research questions with respect to satellite and terrestrial network convergence.This work was supported by the BATS Research Project through the European Union Seventh Framework Programme under Contract 317533
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