Metro Ethernet -tekniikka: verkko, palvelut ja suunnittelu

Työ aloitettiin perehtymällä Metro Ethernet verkon eriosiin kuten Ethernet-verkkoon, MultiProtocol Label Switching verkkoon ja näiden verkkojen eriosiin. Työssä siis tarkasteltiin lähemmin Ethernet verkon toimintaa sekä sen tarjoamia standardeja kaistannopeuteen, kaapeli materiaaleihin ja kehysrakenteeseen. Tarkasteltiin myös MultiProtocol Label Swit-ching verkon rakennetta, pakettien reititys perusteita pohjautuen Ethernet verkon kehysrakenteeseen, Internet Protocol over MultiProtocol Label Switching tekniikkaa sekä näihin liittyviä alakäsitteitä kuten palvelunlaatu, virtuaaliyhteys, MAC-osoite jne. Kun työssä oli selvitetty Metro Ethernet verkon taustat ja perusteet voitiin siirtyä tutkimaan Metro Area Network ja Metro Ethernet Networks verkkojen tarkempaa rakennetta ja niiden mahdollisuuksia. Koska työn aiheena on Metro Ethernet-verkko, tulee myös tutkia Metro Ethernet Forum järjestöä jossa päätetään kaikki Metro Ethernet-verkkoon liittyvät asiat ja mm. MEF standardit. MEF standardeja on 16 kappaletta ja ne määrittelevät mm. Metro Ethernet verkon palvelut ja verkon arkkitehtuurin. Viimeisenä tutkimusalueena oli kolmen eri verkkolaitteen tutkiminen ja jo valmiina olevien verkkolaitteiden mahdollisuuksien kartoitus. Laitteiden tutkinnassa perehdyttiin Metro Et-hernet-verkko mahdollisuuksiin jokaisen laitevalmistajan tarjoamalla Internet Protocol over MultiProtocol Label Switching tekniikalla. Lopuksi tutkittiin vielä verkkosuunnitelman poh-jan luomista sekä itse suunnitelmaa, aikaisempien tutkimus tulosten pohjalle. Tutkimuksen tuloksena saatiin Metro Ethernet verkon ja käyttökelpoisten verkkolaitteiden tutkimusraportti ja käyttökelpoinen Metro Ethernet-verkkosuunnitelma jota voi käyttää mahdollisesti suoraan pohjana tai ainakin vertailu pohjana käytännön toteutuksessa.

Captura i filtrat de paquets a xarxesEthernet

Aquest treball se centra en les tècniques de captura i filtratge de paquets a xarxes Ethernet. Com objectiu principal ens hem fixat l¿estudi de les estructures implementades pel sistema operatiu i la interfície oferta als programadors per tal de poder utilitzar-la. Com a objectiu secundari pretenem, posar a la practica els coneixements obtinguts i desenvolupar un producte sòlid i robust en la seva funcionalitat bàsica, filtrar i capturar paquets, però que sigui extensible a altres aplicacions orientades a xarxa. Anàlisis de rendiment de la xarxa, per exemple.

Schedulability analysis of generalized multiframe traffic on multihop-networks comprising software-implemented ethernet switches

Consider a multihop network comprising Ethernet switches. The traffic is described with flows and each flow is characterized by its source node, its destination node, its route and parameters in the generalized multiframe model. Output queues on Ethernet switches are scheduled by static-priority scheduling and tasks executing on the processor in an Ethernet switch are scheduled by stride scheduling. We present schedulability analysis for this setting.

Ethernet-based systems: contributions to the holistic analysis

A number of characteristics are boosting the eagerness of extending Ethernet to also cover factory-floor distributed real-time applications. Full-duplex links, non-blocking and priority-based switching, bandwidth availability, just to mention a few, are characteristics upon which that eagerness is building up. But, will Ethernet technologies really manage to replace traditional Fieldbus networks? To this question, Fieldbus fundamentalists often argue that the two technologies are not comparable. In fact, Ethernet technology, by itself, does not include features above the lower layers of the OSI communication model. Where are the higher layers that permit building real industrial applications? And, taking for free that they are available, what is the impact of those protocols, mechanisms and application models on the overall performance of Ethernetbased distributed factory-floor applications? In this paper we provide some contributions that may pave the way towards providing some reasonable answers to these issues.

From simulation to statistical analysis: timeliness assessment of ethernet/IP-based distributed systems

A number of characteristics are boosting the eagerness of extending Ethernet to also cover factory-floor distributed real-time applications. Full-duplex links, non-blocking and priority-based switching, bandwidth availability, just to mention a few, are characteristics upon which that eagerness is building up. But, will Ethernet technologies really manage to replace traditional Fieldbus networks? Ethernet technology, by itself, does not include features above the lower layers of the OSI communication model. In the past few years, it is particularly significant the considerable amount of work that has been devoted to the timing analysis of Ethernet-based technologies. It happens, however, that the majority of those works are restricted to the analysis of sub-sets of the overall computing and communication system, thus without addressing timeliness at a holistic level. To this end, we are addressing a few inter-linked research topics with the purpose of setting a framework for the development of tools suitable to extract temporal properties of Commercial-Off-The-Shelf (COTS) Ethernet-based factory-floor distributed systems. This framework is being applied to a specific COTS technology, Ethernet/IP. In this paper, we reason about the modelling and simulation of Ethernet/IP-based systems, and on the use of statistical analysis techniques to provide usable results. Discrete event simulation models of a distributed system can be a powerful tool for the timeliness evaluation of the overall system, but particular care must be taken with the results provided by traditional statistical analysis techniques.

Industrial ethernet: building blocks for a holistic approach

For industrial environments it is true that Ethernet technologies are there to stay. In fact, a number of characteristics are boosting the eagerness of extending Ethernet to also cover factory-floor applications. Fullduplex links, non-blocking and priority-based switching, bandwidth availability, just to mention a few, are characteristics upon which that eagerness is building up. But, will Ethernet technologies really manage to replace traditional field bus networks? Fieldbus fundamentalists often argue that the two things are not comparable. In fact, Ethernet technology, by itself, does not include features above the lower layers of the OSI communication model. Where are the higher layers and the application enablers that permit building real industrial applications? And, taking for free that they are available, what is the impact of those protocols, mechanisms and application models on the overall performance of Ethernet-based distributed factory-floor applications?

Simple and stable dynamic traffic engineering for provider scale ethernet

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia Informática

Resource management research in Passive Optical Networks (PON)

Next Generation Access Networks (NGAN) are the new step forward to deliver broadband services and to facilitate the integration of different technologies. It is plausible to assume that, from a technological standpoint, the Future Internet will be composed of long-range high-speed optical networks; a number of wireless networks at the edge; and, in between, several access technologies, among which, the Passive Optical Networks (xPON) are very likely to succeed, due to their simplicity, low-cost, and increased bandwidth. Among the different PON technologies, the Ethernet-PON (EPON) is the most promising alternative to satisfy operator and user needs, due to its cost, flexibility and interoperability with other technologies. One of the most interesting challenges in such technologies relates to the scheduling and allocation of resources in the upstream (shared) channel. The aim of this research project is to study and evaluate current contributions and propose new efficient solutions to address the resource allocation issues in Next Generation EPON (NG-EPON). Key issues in this context are future end-user needs, integrated quality of service (QoS) support and optimized service provisioning for real time and elastic flows. This project will unveil research opportunities, issue recommendations and propose novel mechanisms associated with the convergence within heterogeneous access networks and will thus serve as a basis for long-term research projects in this direction. The project has served as a platform for the generation of new concepts and solutions that were published in national and international conferences, scientific journals and also in book chapter. We expect some more research publications in addition to the ones mentioned to be generated in a few months.

Suunnitelma Ethernet-pohjaisen TCP/IP-verkon toteuttamiseksi prosessitietoliikenteen tarpeisiin Helsingin Energiassa

Prosessitietoliikenneverkko toimii mm. energian tuotannon, siirron ja jakelun käytönvalvontajärjestelmien tiedonsiirron alustana. Tietoliikenneverkkojen rooli osana yrityksen operatiivisia prosesseja kasvaa järjestelmäuusintojen myötä ja järjestelmien tehokas hyödyntäminen vaatii luotettavat sekä nopeat tietoverkot. Uusittavien järjestelmien tietoliikenneratkaisut perustuvat pääsääntöisesti Ethernetpohjaiseen TCP/IP-verkkotekniikkaan. Tällä hetkellä prosessijärjestelmien tiedonsiirtoyhteydet kenttälaitteiden ja valvomojärjestelmien välillä on pääsääntöisesti toteutettu PCM-siirtojärjestelmällä tai kiinteän yhteyden modeemeilla. Käytössä oleva PCM-tekniikka on elinkaarensa loppupuolella ja tiedonsiirtonopeudet sekä liityntärajapinnat eivät täytä nykyaikaisten prosessijärjestelmien tiedonsiirto¬vaatimuksia. Työssä käytiin läpikeskeisimmät Ethernet-tekniikkaan ja TCP/IP-protokollaperheeseen liittyvät standardit ja verkon aktiivilaitteet. Vaatimusmäärittelyissä selvitettiin Helsingin Energian eri liiketoimintayksiköiden tarpeita sekä energia-alan lainsäädännön vaatimuksia prosessitietoliikenneverkolle. Tarpeiden ja vaatimusten pohjalta verrattiin kolmea eri vaihtoehtoista verkkotekniikkaa: kytkintekniikkaa, reititintekniikkaa ja MPLS-tekniikkaa. Vertailun perusteella valitulla verkkotekniikalla tehtiin suunnitelma avoimesta, valmistajasta riippumattomasta standardeihin perustuvasta yritystason Ethernet-pohjaisesta TCP/IP prosessiverkkoratkaisusta. Johtopäätöksissä pohditaan valitun ratkaisun käytettävyyttä, tietoturvaa sekä toimenpiteitä niiden kehittämiseksi.

Improving Label Space Usage for Ethernet Label Switched Paths

Ethernet is becoming the dominant aggregation technology for carrier transport networks; however, as it is a LAN technology, native bridged ethernet does not fulfill all the carrier requirements. One of the schemes proposed by the research community to make ethernet fulfill carrier requirements is ethernet VLAN-label switching (ELS). ELS allows the creation of label switched data paths using a 12-bit label encoded in the VLAN TAG control information field. Previous label switching technologies such as MPLS use more bits for encoding the label. Hence, they do not suffer from label sparsity issues as ELS might. This paper studies the sparsity issues resulting from the reduced ELS VLAN-label space and proposes the use of the label merging technique to improve label space usage. Experimental results show that label merging considerably improves label space usage

Communication Solutions for LVDC Island Networks

Production and generation of electrical power is evolving to more environmental friendly technologies and schemes. Pushed by the increasing cost of fossil fuels, the operational costs of producing electrical power with fossil fuels and the effect in the environment, like pollution and global warming, renewable energy sources gain con-stant impulse into the global energy economy. In consequence, the introduction of distributed energy sources has brought a new complexity to the electrical networks. In the new concept of smart grids and decen-tralized power generation; control, protection and measurement are also distributed and requiring, among other things, a new scheme of communication to operate with each other in balance and improve performance. In this research, an analysis of different communication technologies (power line communication, Ethernet over unshielded twisted pair (UTP), optic fiber, Wi-Fi, Wi-MAX, and Long Term Evolution) and their respective characteristics will be carried out. With the objective of pointing out strengths and weaknesses from different points of view (technical, economical, deployment, etc.) to establish a richer context on which a decision for communication approach can be done depending on the specific application scenario of a new smart grid deployment. As a result, a description of possible optimal deployment solutions for communication will be shown considering different options for technologies, and a mention of different important considerations to be taken into account will be made for some of the possible network implementation scenarios.

Carrier Ethernet "label" scalability

A collection of slides from the authorpsilas seminar presentation is given

Improving Label Space Usage for Ethernet Label Switched Paths

Ethernet is becoming the dominant aggregation technology for carrier transport networks; however, as it is a LAN technology, native bridged ethernet does not fulfill all the carrier requirements. One of the schemes proposed by the research community to make ethernet fulfill carrier requirements is ethernet VLAN-label switching (ELS). ELS allows the creation of label switched data paths using a 12-bit label encoded in the VLAN TAG control information field. Previous label switching technologies such as MPLS use more bits for encoding the label. Hence, they do not suffer from label sparsity issues as ELS might. This paper studies the sparsity issues resulting from the reduced ELS VLAN-label space and proposes the use of the label merging technique to improve label space usage. Experimental results show that label merging considerably improves label space usage

Improving resource utilization in carrier ethernet technologies

Ethernet está empezando a pasar de las redes de área local a una red de transporte. Sin embargo, como los requisitos de las redes de transporte son más exigentes, la tecnología necesita ser mejorada. Esquemas diseñados para mejorar Ethernet para que cumpla con las necesidades de transporte se pueden categorizar en dos clases. La primera clase mejora solo los componentes de control de Ethernet (Tecnologías basadas en STP), y la segunda clase mejora tanto componentes de control como de encaminamiento de Ethernet (tecnologías basadas en etiquetas). Esta tesis analiza y compara el uso de espacio en las etiquetas de las tecnologias basadas en ellas para garantizar su escalabilidad. La aplicabilidad de las técnicas existentes y los estudios que se pueden utilizar para superar o reducir los problemas de escalabilidad de la etiqueta son evaluados. Además, esta tesis propone un ILP para calcular el óptimo rendimiento de las technologias basadas en STP y las compara con las basadas en etiquetas para ser capaz de determinar, dada una específica situacion, que technologia utilizar.

Proposta para minimizar penalidade do tráfego de melhor esforço (BE) em redes óticas passivas ethernet (EPON): análise através de modelo híbrido analítico/simulado

Neste trabalho, propõe-se uma melhoria na estratégia de escalonamento baseada em pesos das classes de tráfego em redes óticas passivas Ethernet – EPON, de modo a não penalizar demasiadamente a classe tipo melhor esforço (BE). Como suporte, desenvolveu-se um modelo híbrido analítico/simulado para análise de desempenho do fluxo de subida, baseado no atraso total de quadros. A modelagem foi feita utilizando Redes de Petri Coloridas Estocásticas (Stochastic Colored Petri Nets - SCPN) da qual se obtém, por simulação, o tamanho médio da fila que posteriormente é usado para, analiticamente, obter-se o atraso total. Não obstante ao crescimento de aplicações multimídia em tempo real, no ano de 2010, o tráfego tradicional na Internet (navegação web, email, mensagens instantâneas) classificado como melhor esforço ainda foi responsável, sozinho (excluindo transferência de arquivos P2P), por valores em torno de 18% do tráfego na Internet. Somando-se a este percentual as aplicações P2P, que também não são essencialmente sensíveis ao atraso, têm-se uma participação de 58% (o tráfego P2P foi no ano de 2010 responsável por aproximadamente 40% do volume total de informações trafegadas na Internet). Mesmo em previsões feitas para o ano de 2014 o tráfego BE ainda representará aproximadamente 40% do volume total de dados a serem trafegados nas redes IPs mundiais. Estes números demonstram que a preocupação com este tipo de tráfego não pode ser relegada a uma importância secundária em detrimento às aplicações que exigem maior qualidade de serviço. Tomando como base o escalonamento IPACT (Interleaved Polling with Adapting Cycle Time) esta dissertação demonstra que é possível, através da melhoria proposta, obter atrasos menores no tráfego de melhor esforço, sem que as classes de tráfego prioritárias ultrapassem as especificações de atraso recomendadas para cada uma destas.