Dissertations / Theses on the topic 'VnfG'

Biological nitrogen fixation is accomplished in the bacterium Azotobacter vinelandii by means of three metalloenzymes: The molybdenum, vanadium, and iron-only nitrogenase. The knowledge regarding biological nitrogen fixation has come from studies on the Mo-dependent reaction. However, the V- and Fe-only-dependent reduction of nitrogen remains largely unknown. By using homology modeling techniques, the protein folds that contain the metal cluster active sites for the V- and Fe-only nitrogenases were constructed. The models uncovered similarities and differences existing among the nitrogenases regarding the identity of the amino acid residues lining pivotal structural features for the correct functioning of the proteins. These differences, could account for the differences in catalytic properties depicted by these enzymes. The quaternary structure of the dinitrogenases also differs. Such component in the Mo-nitrogenase is an α2β2 tetramer while for the V- an Fe-only nitrogenase is an α2β2δ2 hexamer. The latter enzymes are unable to reduce N2 in the absence of a functional δ subunit, yet they reduce H+ and the non-physiological substrate C2H2. Therefore, the δ subunit is essential for V- and Fe-only dependent nitrogen fixation by a mechanism that still remains unknown. In attempt to understand why the δ subunit is essential for V-dependent N2 reduction from a structural stand point, this work presents the strategy followed to clone the vnfG gene and purify its expression product, the δ subunit. The purified protein was subjected to crystallization trials and used to stabilize a histidine-tagged VFe protein that would otherwise purify with low Fe2+ content and poor H+ and C2H2 reduction activities. The VFe preparation was used to conduct substrate reduction assays to assess: i) The electron allocation patterns to each of the reduction products of the substrates C2H2, N2, N2H4, and N3−; and ii) Inhibition patterns among substrate and inhibitor of the nitrogenase reaction. This work also reports on the effect N2H4 and N3− has on the electron flux to the products of the C2H2 reduction. The work presented herein provides information with which to compare and contrast biological nitrogen fixation as catalyzed by the Mo- and V-nitrogenases from Azotobacter vinelandii.

La Network Function Virtualisation (NFV) è la principale forza dietro la migrazione delle infrastrutture dei provider di reti verso sistemi distribuiti cloud, fornendo un innovativo approccio al design di architetture di reti di telecomunicazioni che permette un completo disaccoppiamento dei servizi offerti dalla rete dai dispositivi fisici e gli apparati su cui essi risiedono attraverso la loro completa virtualizzazione. L’uso di VNF, blocchi logici in grado di rappresentare le funzionalità e i servizi forniti dall’infrastruttura come elementi virtuali, permette alle Network Functions di essere agevolmente rilocate in data centers prossimi agli utenti finali dei servizi che offrono, evitando i pesanti costi in personale ed apparecchiature coinvolti nel caso dei dispositivi fisici. ETSI NFV fornisce linee guida ed architetture volte al supportare l’amministrazione ed orchestrazione (MANO) di apparati virtualizzati, sfruttando le infrastrutture fornite da Virtual Infrastructure Managers (VIM). Questa tesi ha affrontato le modalità con cui un framework NFV esistente, come Open Baton, possa essere esteso per sfruttare appieno le capacità fornite da sistemi di containerizzazione come Docker, realizzando i componenti e concetti necessari per offrire una infrastruttura NFV (NFVI) altamente scalabile e cloud-ready. Il prototipo di VIM basato su Docker e i relativi componenti MANO sviluppati durante questa tesi sono stati pensati per essere il più possibile indipendenti fra loro, per mantenere il sistema riusabile ed aperto ad estensioni future. L’analisi compiuta sulla soluzione per l’orchestrazione di container NFV basata su Docker creata durante lo step implementativo della tesi ha mostrato risultati molto positivi riguardo l’overhead sull’utilizzo di risorse di memoria e di storage da parte delle istanze di VNF basate su container.

This master’s thesis explains why certain network services are difficult to provision and configure using IT automation and cloud orchestration software. An improvement is proposed and motivated. This proposed improvement enables network operators to define a set of data models describing how to provision and interconnect a set of Virtual Network Functions (VNFs) (and possibly existing physical network functions) to form networks. Moreover, the proposed solution enables network operators to change the configuration at runtime. The work can be seen as a step towards self managing and auto scaling networks. The proposed approach is compared to a well known cloud management system (OpenStack) in order to evaluate if the proposed approach decreases the amount of time needed for network operators to design network topologies and services containing VNFs. Data is collected through observations of network operators, interviews, and experiment. Analysis of this data shows that the proposed approach can decrease the amount of time required for network operators to design network topologies and services. This applies if the network operators are already acquainted with the data modeling language YANG. The amount of time required to provision VNFs so that they respond to connections can also be decreased using the proposed approach. The proposed approach does not offer as much functionality as OpenStack, as it is limited to VNF scenarios.
Denna masteruppsats förklarar varför vissa nätverkstjänster är svåra att skapa och konfigurera med IT-automationsverktyg och mjukvara för molnorkestrering.  En förbättring föreslås och motiveras. Den föreslagna förbättringen tillåter nätverksoperatörer att definiera en mängd datamodeller, för att beskriva hur Virtuella Nätverksfunktioner (VNF:er) skall instantieras och kopplas ihop till nätverkstjänster. Dessutom tillåter lösningen nätverksoperatörer att ändra konfiguration under tiden nätverken hanterar trafik.  Arbetet kan ses som ett steg mot självhanterande och automatiskt skalande nätverk. Den föreslagna lösningen jämförs med ett välkänt molnorkestreringsverktyg (OpenStack) för att utvärdera om den föreslagna lösningen sänker mängden tid som nätverksoperatörer behöver för att designa nätverkstopologier och tjänster som innehåller VNF:er. Data samlas in genom observationer av nätverksoperatörer, intervjuer, och experiment. Analys av datan visar att den föreslagna lösningen kan minska tiden som behövs för att designa nätverkstopologier och tjänster. Fallen där detta är applicerbart, är när VNF:er närvarar i nätverk. Dessa är enklare att skapa, konfigurera, och ändra under tiden de exekverar, med den föreslagna metoden. Detta kräver också att nätverksoperatören är bekant med datamodelleringsspråket YANG. Tiden det tar att provisionera VNF:er, tills dess att de svarar till anslutningar, kan sänkas med hjälp av den föreslagna metoden. Den förslagna metoden erbjuder väsentligt begränsad funktionalitet jämfört med OpenStack, den fokuserar på att hantera VNF:er.

Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-08-01T19:46:31Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Danyel Mendes Nogueira Ramos.pdf: 6326279 bytes, checksum: 464556d46f78d9d42c7353434472dab5 (MD5)
Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-08-02T20:38:26Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Danyel Mendes Nogueira Ramos.pdf: 6326279 bytes, checksum: 464556d46f78d9d42c7353434472dab5 (MD5)
Made available in DSpace on 2018-08-02T20:38:26Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Danyel Mendes Nogueira Ramos.pdf: 6326279 bytes, checksum: 464556d46f78d9d42c7353434472dab5 (MD5) Previous issue date: 2017-04-04
SETEC
A implementação de serviços de rede em dispositivos embarcados proprietários tem impedido o avanço e a evolução da rede, induzindo um problema denominado ossificação. Aproveitando os benefícios da virtualização, NFV se constitui em uma abordagem que dissocia os serviços de rede do hardware subjacente, permitindo a virtualização de funções de rede em servidores de propósito geral resultando em redução de OPEX/CAPEX. Integrado com SDN, a arquitetura NFV Definida por Software tem o potencial de oferecer mais agilidade e flexibilidade no encaminhamento de tráfego e no encadeamento de funções, justificando-se a importância de avaliarmos um controlador SDN implementado como uma NFV, com o objetivo de verificarmos as implicações no desempenho, uma vez que estudos recentes demonstram a degradação de desempenho imposta pela virtualização de funções de rede. No presente trabalho, realizamos experimentos com um controlador SDN implementado como uma função de rede virtual nos hypervisores de código aberto KVM e XEN e comparamos os parâmetros de desempenho mais críticos em relação a um cenário nativo com o propósito de mensurar a degradação de desempenho causada pela virtualização. Cbench foi utilizado para emular redes SDN e avaliar o desempenho e a latência do controlador Floodlight. Os resultados mostram que a virtualização do controlador no ambiente KVM resultou na degradação do processamento de fluxos em 29%, apresentou um aumento do tempo de resposta de 22% e utilizou bem menos o processador em relação ao ambiente Xen, que sobrecarregou a CPU em 25%, mas foi capaz de atingir melhor throughput e alocação de memória RAM quando comparada ao controlador virtualizado em KVM. Finalmente, uma proposta de aplicação SDN de roteamento de QoS e a respectiva infraestrutura NFV de implantação é apresentada como estudo de caso na autarquia federal IF Sertão-PE.
The implementation of network services in proprietary embedded devices has prevented the advancement and evolution of the network, inducing a problem called ossification. Leveraging the benefits of virtualization, NFV is an approach that disassociates network services from the underlying hardware, enabling virtualization of network functions on general purpose servers resulting in OPEX / CAPEX reduction. Integrated with SDN, the Software Defined NFV architecture has the potential to offer more agility and flexibility in traffic routing and in the chain of functions, justifying the importance of evaluating an SDN controller implemented as an NFV, in order to verify the Implications for performance, as recent studies demonstrate the performance degradation imposed by virtualization of network functions. In the present work, we performed experiments with an SDN controller implemented as a virtual network function in the KVM and XEN open source hypervisors and compared the most critical performance parameters in relation to a native scenario in order to measure the degradation of performance caused by Virtualization. We use Cbench to emulate SDN networks and evaluate the performance and latency of the Floodlight controller. We found that virtualization of the controller in the KVM environment resulted in degradation of the processing of flows by 29%, showed an increase in the response time of 22% and used much less the processor in relation to Xen, which overloaded the CPU by 15%, but Was able to achieve better performance of throughput and RAM compared to the virtualized controller in KVM. Finally, a proposed SDN routing QoS application and the respective deployment NFV infrastructure is presented as a case study in the federal authority IF Sertão-PE.

Managing and orchestrating the behaviour of virtualized Network Functions (VNFs) remains a major challenge due to their heterogeneity and the ever increasing resource demands of the served flows. In this thesis, we propose a novel VNF manager (VNFM) that employs a parameterized actions-based reinforcement learning mechanism to simultaneously decide on the optimal VNF management action (e.g., migration, scaling, termination or rebooting) and the action's corresponding configuration parameters (e.g., migration location or amount of resources needed for scaling ). More precisely, we first propose a novel parameterized-action Markov decision process (PAMDP) model to accurately describe each VNF, instances of its components and their communication as well as the set of permissible management actions by the VNFM and the rewards of realizing these actions. The use of parameterized actions allows us to rigorously represent the functionalities of the VNFM in order perform various Lifecycle management (LCM) operations on the VNFs. Next, we propose a two-stage reinforcement learning (RL) scheme that alternates between learning an action-value function for the discrete LCM actions and updating the actions parameters selection policy. In contrast to existing machine learning schemes, the proposed work uniquely provides a holistic management platform the unifies individual efforts targeting individual LCM functions such as VNF placement and scaling. Performance evaluation results demonstrate the efficiency of the proposed VNFM in maintaining the required performance level of the VNF while optimizing its resource configurations.

The evolution of information and communication technologies (e.g. cloud computing, the Internet of Things (IoT) and 5G, among others) has enabled a large market of applications and network services for a massive number of users connected to the Internet. Achieving high programmability while decreasing complexity and costs has become an essential aim of networking research due to the ever-increasing pressure generated by these applications and services. However, meeting these goals is an almost impossible task using traditional IP networks. Software-Defined Networking (SDN) is an emerging network architecture that could address the needs of service providers and network operators. This new technology consists in decoupling the control plane from the data plane, enabling the centralization of control functions on a concentrated or distributed platform. It also creates an abstraction between the network infrastructure and network applications, which allows for designing more flexible and programmable networks. Recent trends of increased user demands, the explosion of Internet traffic and diverse service requirements have further driven the interest in the potential capabilities of SDN to enable the introduction of new protocols and traffic management models. This doctoral research is focused on improving high-level policies and control strategies, which are becoming increasingly important given the limitations of current solutions for large-scale SDN environments. Specifically, the three largest challenges addressed in the development of this thesis are related to the processes of topology discovery, fault recovery and Virtual Network Function (VNF) placement in software-defined and virtualized networks. These challenges led to the design of a set of effective techniques, ranging from network protocols to optimal and heuristic algorithms, intended to solve existing problems and contribute to the deployment and adoption of such programmable networks.For the first challenge, this work presents a novel protocol that, unlike existing approaches, enables a distributed layer 2 discovery without the need for previous IP configurations or controller knowledge of the network. By using this mechanism, the SDN controller can discover the network view without incurring scalability issues, while taking advantage of the shortest control paths toward each switch. Moreover, this novel approach achieves noticeable improvement with respect to state-of-the-art techniques. To address the resilience concern of SDN, we propose a self-healing mechanism that recovers the control plane connectivity in SDN-managed environments without overburdening the controller performance. The main idea underlying this proposal is to enable real-time recovery of control paths in the face of failures without the intervention of a controller. Obtained results show that the proposed approach recovers the control topology efficiently in terms of time and message load over a wide range of generated networks. The third contribution made in this thesis combines topology knowledge with bin packing techniques in order to efficiently place the required VNF. An online heuristic algorithm with low-complexity was developed as a suitable solution for dynamic infrastructures. Extensive simulations, using network topologies representative of different scales, validate the good performance of the proposed approaches regarding the number of required instances and the delay among deployed functions. Additionally, the proposed heuristic algorithm improves the execution times by a fifth order of magnitude compared to the optimal formulation of this problem.

Virtual Network Functions (VNFs) are software applications that process network packets in virtualized environments such as clouds. Using VNFs to process network traffic inside a cloud, which could be controlled by a third-party, exposes the secrets that are stored within the VNFs to a significant amount of threats. Trusted Execution Environments (TEEs) are hardware technologies dedicated to protect software from other malicious applications and users. Open Enclave and Asylo are two SDKs that decouple software and hardware and enable developers to build applications that utilize TEEs without creating hardware dependencies. Open Enclave and Asylo are still in an early stage of development, Asylo in particular. The impact of integrating Open Enclave and Asylo to VNFs from a security and performance perspective was addressed by performing a risk assessment and running performance experiments. The identified vulnerabilities in VNFs were mitigated by using available security properties from TEEs. The results show that protecting VNFs with Open Enclave and Asylo mitigate a significant amount of threats. However, the VNFs suffer from a performance penalty when using TEEs, and are still vulnerable to side-channel and Denial-of-Service attacks.

The semicircular canals are involved in the coding of angular acceleration of the head and body. Presently, video-nystagmography (VNG) and specifically, caloric testing, is the gold standard for evaluation of semicircular canal function. Caloric irrigation via VNG can only evaluate horizontal semicircular canal function; with this test, there is no way to evaluate the function of the anterior and posterior vertical semicircular canals. The video Head Impulse Test (vHIT) is a relatively new protocol that has the capability to test the function of the horizontal, anterior vertical, and posterior vertical semicircular canals. Because the vHIT system is newly available to clinicians, there is a need to collect normative data, particularly for the vertical semicircular canals. For this study, data was collected from 12 participants with no complaint or history of balance difficulty. Additionally, we compared our data with normative data collected in an earlier study to determine consistency. Lateral average velocity gain measurements were consistent however, a comparison of RALP an LARP velocity gain measurements showed inconsistency.

Des solutions de vérification efficaces nous semblent indispensables afin d’assurer la continuité des services en place et le déploiement de nouveaux services dans les réseaux 5G. Cette problématique ne se limite pas aux techniques de vérification, nos travaux portent aussi sur la formalisation des besoins d'un service réseau complet. Nous avons travaillé sur un langage de programmation facilitant la vérification dans les contrôleurs SDN. Puis nous avons défini des contrats de comportement réseau afin de clarifier les propriétés à vérifier pour assurer le bon fonctionnement d'un service. Enfin nous avons étudié MANO pour proposer une extension du standard permettant de vérifier les configurations réseau au niveau de l'orchestrateur
We believe that effective verification solutions are essential to ensure the continuity of existing services and the deployment of new services in 5G networks. This problem is not limited to verification techniques, our work also concerns the formalization of needs of a complete network service. We worked on a programming language to facilitate verification in SDN controllers. Then we defined network behavior contracts to clarify the properties to be verified to ensure the proper functioning of a service. Finally, we studied MANO to propose an extension of the standard to check the network configurations at the orchestrator level

With the upcoming 5G deployment and the exponentially increasing data transmitted over cellular networks, off the shelf hardware won't provide enough performance to cope with the data being transferred over cellular networks. To tackle that problem, hardware accelerators will be of great support thanks to their better performances and lower energy consumption. However, hardware accelerators are not a silver bullet as their very nature prevents them to be as flexible as CPUs. Hardware accelerators integration into Kubernetes and Docker, respectively the most used tools for orchestration and containerization, is still not as flexible as it would need. In this thesis, we developed a framework that allows for a more flexible integration of these accelerators into a Kubernetes cluster using Docker containers making use of an abstraction layer instead of the classic virtualization process. Our results compare the performance of an execution with and without the framework that was developed during this thesis. We found that the framework's overhead depends on the size of the data being processed by the accelerator but does not go over a very low percentage of the total execution time. This framework provides an abstraction for hardware accelerators and thus provides an easy way to integrate hardware accelerated applications into a heterogeneous cluster or even across different clusters with different hardware accelerators types. This framework also moves the hardware specific parts of an accelerated program from the containers to the infrastructure and enables a new kind of service, OpenCL as a service.

Next generation mobile networks are designed to run in a virtualized environment, enabling rapid infrastructure deployment and high flexibility for coping with increasing traffic demands and new service requirements. Such network function virtualization imposes additional packet latencies and potential bottlenecks not present in legacy network equipment when run on dedicated hardware; such bottlenecks include PCIe transfer delays, virtualization overhead, and utilizing commodity server hardware which is not optimized for packet processing operations.Through recent developments in P4 programmable networking devices, it is possible to implement complex packet processing pipelines directly in the network data plane; allowing critical traffic flows to be offloaded and flexibly hardware accelerated on new programmable packet processing hardware, prior to entering the virtualized environment.In this thesis, we design and implement a novel hybrid NFV processing architecture which integrates programmable NICs and commodity server hardware, capable of offloading virtual network functions for specified traffic flows directly to the server network card; allowing these flows to completely bypass softwarization overhead, while less sensitive traffic process on the underlying host server.An evaluation in a testbed with customized traffic generators show that accelerated flows have significantly lower jitter and latency, compared with flows processed on commodity server hardware. Our evaluation gives important insights into the designs of such hardware accelerated virtual network deployments, showing that hybrid network architectures are a viable solution for enabling infrastructure scalability without sacrificing critical flow performance.

Le but de cette thèse est d’étudier et d’évaluer le rôle de la virtualisation des réseau de diffusion de contenu. Nous proposons une implémentation d’une architecture CDN permettant à un opérateur de réseau de virtualiser son infrastructure CDN et de la louer à des fournisseurs de contenu. Afin d’avoir une allocation optimale des ressources, nous proposons une méthode qui combine les informations fournies lors de la demande par le fournisseur de contenu avec les données du réseau et de l’infrastructure de calcul. Nous avons modélisé ce problème d’allocation de ressources en problème d’optimisation, résolu par un algorithme. Les résultats obtenues donnent suite à la proposition d’algorithmes et d’heuristiques de placement pour l’allocation conjointe de vCPU-à-VM et le placement des VMs dans les Pms
The goal of this thesis is to study and evaluate the role a Virtual CDNs in improving the end-users QoE while saving on service providers’ costs and service availability. First, we present the design and implementation of an architecture for on-demand deployment of a vCDN infrastructure over a telco cloud. Second, we propose different algorithms for solving the Virtual Network Function (VNF) placement problem. We propose a polynomialtime heuristic algorithms to solve a relaxed version of the problem’s assumptions, we show experimentally that the derived solutions are close to the optimal. Finally, we study and evaluate solutions for the placement of VNF at the edge, by moving from the traditional central cloud to the edge one. We have also shown how our method can reduce delays and still provide a highly-available service

A datacenter hosts hundreds of thousands of servers and a huge amount of bandwidth is required to accommodate communication between thousands of servers. Several packet switched based datacenter architectures are proposed to cater the high bandwidth requirement using multilayer network topologies, however at the cost of increased network complexity and high power consumption. In recent years, the focus has shifted from packet switching to optical circuit switching to build the data center networks as it can support on demand connectivity and high bit rates with low power consumption. On the other hand, with the advent of Software Defined Networking (SDN) and Network Function Virtualization (NFV), the role of datacenters has become more crucial. It has increased the need of dynamicity and flexibility within a datacenter adding more complexity to datacenter networking. With NFV, service chaining can be achieved in a datacenter where virtualized network functions (VNFs) running on commodity servers in a datacenter are instantiated/terminated dynamically. A datacenter also needs to cater large capacity requirement as service chaining involves steering of large aggregated flows. Use of optical circuit switching in data center networks is quite promising to meet such dynamic and high capacity traffic requirements. In this thesis work, a novel and modular optical data center network (DCN) architecture that uses multi-directional wavelength switches (MD-WSS) is introduced. VNF service chaining use case is considered for evaluation of this DCN and the end-to-end service chaining problem is formulated as three inter-connected sub-problems: multiplexing of VNF service chains, VNFs placement in the datacenter and routing and wavelength assignment. This thesis presents integer linear programming (ILP) formulation and heuristics for solving these problems, and numerically evaluate them.
Ett datacenter inrymmer hundratusentals servrar och en stor mängd bandbredd krävs för att skicka data mellan tusentals servrar. Flera datacenter baserade på paketförmedlande arkitekturer föreslås för att tillgodose kravet på hög bandbredd med hjälp av flerskiktsnätverkstopologier, men på bekostnad av ökad komplexitet i nätverken och hög energiförbrukning. Under de senaste åren har fokus skiftat från paketförmedling till optisk kretsomkoppling for att bygga datacenternätverk som kan stödja på-begäran-anslutningar och höga bithastigheter med låg strömförbrukning. Å andra sidan, med tillkomsten av Software Defined Networking (SDN) och nätverksfunktionen Virtualisering (NFV), har betydelsen av datacenter blivit mer avgörande. Det har ökat behovet av dynamik och flexibilitet inom ett datacenter, vilket leder till storre komplexitet i datacenternätverken. Med NFV kan tjänstekedjor åstadkommas i ett datacenter, där virtualiserade nätverksfunktioner (VNFs) som körs på servrar i ett datacenter kan instansieras och avslutas dynamiskt. Ett datacenter måste också tillgodose kravet på stor kapacitet eftersom tjänstekedjan innebär styrning av stora aggregerade flöden. Användningen av optisk kretsomkoppling i datacenternätverk ser ganska lovande ut for att uppfylla sådana trafikkrav dynamik och hög kapacitet. I detta examensarbete, har en ny och modulär optisk datacenternätverksarkitektur (DCN) som använder flerriktningvåglängdsswitchar (MD-WSS) införs. Ett användningsfall av VNF-tjänstekedjor noga övervägd för utvärdering av denna DCN och end-to-end-servicekedjans problem formuleras som tre sammankopplade delproblem: multiplexering av VNF-servicekedjor, VNF placering i datacentret och routing och våglängd uppdrag. Denna avhandling presenterar heltalsprogrammering (ILP) formulering och heuristik för att lösa dessa problem och numeriskt utvärdera dem.

Today Network Function Virtualization (NFV) is one of the fields in telecommunications that is developing and growing at the fastest pace as a fundamental element in the Telco equipment marketplace. Network Functions that have traditionally been deployed over proprietary hardware now are remarkably decoupling of that, taking the functions and moving them into the software and putting them into the common hardware. There are a lot of elements which are moving to software such as IMS, Mobile Core, PE Router, etc. IMS is just one of them, and even within IMS architecture there are significant elements include the CSCF, the HSS, the SBC, the MRF, voice application servers which are starting to move to NFV and each of these elements considered to be a virtual network function (VNF). Migration to the virtual IMS bring the operators the benefits of lower cost regarding CAPEX, fast scaling services, introducing fast new network services, reducing complexity, operational efficiency, etc. In the future, testing network elements will be more necessary since the aim is to implement as software as an on-demand service similar in networks for some aspects such as protocol compliance performance. Moreover, load balancing can join with Software Defined Networking (SDN) to bring the possibility to vary routing of the packets in an NFV enabled network, but routing is not mandatory to be by the software. This dissertation presents the testing on the general NFV and, particularly it study the testing on a network element of virtualized IMS that is Call Session Control Function (CSCF).

La Virtualizzazione è uno dei pilastri fondamentali del Cloud Computing in virtù delle proprietà di isolamento, replicazione e efficiente utilizzo delle risorse. Quando una Virtual Machine (VM), o macchina virtuale, è inattiva (idle), il costo in termini di risorse di CPU e memoria per mantenere in esecuzione la macchina, in attesa di nuove richieste degli utenti, diventa solo un peso per il sistema. Il problema è che spegnere o disattivare queste macchine virtuali inattive libera le risorse ma deteriora la Service Availablility, o disponibilità di servizio, in quanto l'utente si aspetta di trovare sempre raggiungibile la VM. All'interno del team SigNet del laboratorio I3S una soluzione al problema è stata proposta, il suo nome è SEaMLESS. Questa soluzione prevede di trasformare macchine virtuali inattive in leggere Virtual Network Function (VNF) in grado di mantenere la presenza della VM disponibile in rete senza consumare ingenti risorse mentre la macchina virtuale inattiva può essere disattivata in tutta sicurezza. Le risorse liberate possono essere riutilizzate per consolidare le VM attive all'interno di pochi server fisici e quindi risparmiare energia o riciclare la memoria per istanziare nuove macchine virtuali. In questo lavoro di tesi è stato sviluppato un prototipo del sistema SEaMLESS, studiando scenari reali di casi d'uso e valutando le prestazioni, la scalabilità e, in generale, l'impatto sulla qualità del servizio e dell'esperienza provata dall'utente quando il sistema entra in azione. In particolare in questo lavoro sono state trattati in dettaglio i processi di migrazione e rilevamento dell'attività utente che costituiscono le operazioni fondamentale utilizzate da SEaMLESS per disfarsi della VM inattive mantenendo la loro Service Availability intatta. L'idea di SEaMLESS, la sua implementazione e la valutazione del sistema mediante esperimenti sono stati inseriti in un articolo scientifico accettato come poster alla prossima conferenza ACM SoCC'17.

L’objectif de cette thèse est de présenter de nouveaux algorithmes de répartition des ressources sous la forme de machines virtuelles (VMs) et fonction de réseau virtuel (VNFs) dans les Clouds et réseaux de diffusion de contenu (CDNs). La thèse comprend deux principales parties: la première se concentre sur la rentabilité des Clouds distribués, et développe ensuite les raisons d’optimiser les coûts ainsi que les émissions de carbone. Cette partie comprend quatre contributions. La première contribution est une étude de l’état de l’art sur la répartition des coûts et des émissions de carbone dans les environnements de clouds distribués. La deuxième contribution propose une méthode d’allocation des ressources, appelée NACER, pour les clouds distribués. La troisième contribution présente une méthode de placement VM efficace en termes de coûts et de carbone (appelée CACEV) pour les clouds distribués verts. Pour obtenir une meilleure performance, la quatrième contribution propose une méthode dynamique de placement VM (D-CACEV) pour les clouds distribués. La deuxième partie propose des algorithmes de placement de VNFs dans les Clouds et réseaux de CDNs pour optimiser les coûts. Cette partie comprend cinq contributions. Une étude de l’état de l’art sur les solutions proposées est le but de la première contribition. La deuxième contribution propose une méthode d’allocation des ressources, appelée CCVP, pour le provisionnement de service réseau dans les clouds et réseaux de ISP. La troisième contribution implémente le résultat de l’algorithme CCVP dans une plateforme réelle. La quatrième contribution considère l’effet de la permutation de VNFs dans les chaîne de services et la cinquième contribution explique le placement de VNFs pour les services à valeur ajoutée dans les CDNs
High energy costs and carbon emissions are two significant problems in distributed computing domain, such as distributed clouds and Content Delivery Networks (CDNs). Resource allocation methods (e.g., in form of Virtual Machine (VM) or Virtual Network Function (VNF) placement algorithms) have a direct effect on cost, carbon emission and Quality of Service (QoS). This thesis includes three related parts. First, it targets the problem of resource allocation (i.e., in the form of network aware VM placement algorithms) for distributed clouds and proposes cost and carbon emission efficient resource allocation algorithms for green distributed clouds. Due to the similarity of the network-aware VM placement problem in distributed clouds with a VNF placement problem, the second part of the thesis, getting experience from the first part, proposes a new cost efficient resource allocation algorithm (i.e., VNF placement) for network service provision in data centers and Internet Service Provider (ISP) network. Finally, the last part of the thesis presents new cost efficient resource allocation algorithms (i.e., VNF placement) for value-added service provisioning in NFV-based CDNs

Comme le Wi-Fi est devenu de plus en plus important dans les réseaux actuels, ainsi que dans les réseaux du futur, de nouvelles exigences " opérateur " se sont apparues afin de supporter les attentes des utilisateurs et de fournir des réseaux Wi-Fi de haute performance. Dans ce contexte, nous étudions plusieurs problèmes liés à la conception et l'optimisation des réseaux Wi-Fi opérateur de nouvelle génération. Dans la première étape, notre objectif est d'améliorer l'expérience utilisateur Wi-Fi et de lui offrir un accès personnalisé et transparent aux réseaux et services Wi-Fi. Pour cela, nous proposons une extension des trames de gestion IEEE 802.11 pour activer la découverte des services locaux avant l'association Wi-Fi, tout en évitant la surcharge du canal. Nous définissons également un ensemble d'étiquettes de service pour identifier d'une manière standardisée les services les plus connus. Dans la deuxième étape, nous adressons les problèmes liés à l'architecture et la gestion du réseau dans un environnement Wi-Fi opérateur de nouvelle génération. Plus précisément, nous proposons, tout d'abord, une nouvelle architecture Wi-Fi qui exploite les concepts de NFV et du Edge Cloud Computing. Nous visons à travers cette architecture à apporter plus d'agilité et d'adaptabilité et d'améliorer la QoS perçue par l'utilisateur en plaçant des fonctions réseau et certains services à proximité de lui. Pour faire face à certains problèmes de gestion dans cette architecture, nous proposons ensuite des stratégies de placement et de provisionnement des fonctions de réseau virtuelles en s'appuyant sur des exigences de QoS
As Wi-Fi is gaining a lot of momentum in today’s networks as well as in future networks, new carrier-grade requirements are emerging to support future user expectations and provide high-performance Wi-Fi networks. In this context, we investigate several problems surrounding the design and optimization of carrier-grade next-generation Wi-Fi networks. In the first stage, our objective is to improve the Wi-Fi user experience and offer to him a personalized and seamless access to Wi-Fi networks and services. For this, we propose an extension to the IEEE 802.11 management frames to enable venue service discovery prior to Wi-Fi association while avoiding channel overhead. We define also a set of extensible service labels to uniquely and globally identify the most known venue-based services. In the second stage, we deal with network architecture and management issues in next-generation carrier Wi-Fi environment. More specifically, we first propose a novel carrier-managed Wi-Fi architecture that leverages NFV and Edge Cloud Computing concepts. We aim through this architecture to bring more agility and adaptability and improve user perceived QoS by placing network functions and certain services close to end-users. To address some major management issues in this proposed architecture, we then propose placement and provisioning strategies of Virtual Network Functions based on QoS requirements. These strategies can also be applied to any edge-central wireless carrier architecture, since they do not make any assumption about the underlying wireless technology

Gli obiettivi posti dalle nuove generazione di rete sono molto più ambiziosi rispetto al passato e pongono degli ostacoli che possono essere superati solamente adottando un'architettura più evoluta e dei paradigmi per la sua progettazione che consentono di agevolarne la gestione, aumentarne la flessibilità e scalabilità. Le reti mobili attuali, ed in particolare l'infrastruttura sottostante che ne consente il funzionamento, sono costituite da apparecchi hardware dedicati, spesso vincolati a vendor specifici, opportunamente configurati; tali caratteristiche rendono l'architettura rigida, complessa da manutenere e quindi costosa. La volontà di staccarsi da questi vincoli ha portato il mondo delle telecomunicazioni, così come quello dell'informatica ad approcciarsi al cloud ed architetture orientate ai servizi. Il cuore dell'architettura 5G è costituito da un insieme di componenti, in grado di comunicare e/o cooperare con altri componenti mediante apposite interfacce. I paradigmi adottati introducono la possibilità di programmare via software la rete e le sue funzionalità, svincolandosi dal limiti fisici delle apparecchiature hardware che le erogano, agevolandone la progettazione, l'implementazione e la gestione. Le tecnologie di virtualizzazione odierne ci consentono di effettuare il deployment dei servizi di rete in modo agevole; tali servizi inoltre, possono essere orchestrati tramite appositi framework che ne semplificano la gestione ed il dispiegamento automatizzato.

In un periodo in cui tutto si evolve rapidamente, il settore delle telecomunicazioni sta assistendo alla crescita esponenziale del numero di dispositivi mobili costantemente connessi alla rete; ciò richiede la necessità di un nuovo modo di gestire le reti. La nuova visione che sta maturando in questi ultimi tempi è quella di adottare un modello di rete dinamico, flessibile e soprattutto affidabile e che non richieda grossi sforzi di manutenzione o l’installazione di ulteriori hardware da parte degli operatori. Una rete con queste caratteristiche può essere sviluppata grazie ad un modello architetturale innovativo come il Software Defined Networking (SDN) e ad un nuovo modo di sfruttare le funzionalità degli apparati di rete come la Network Function Virtualization (NFV), la quale è a sua volta un processo di virtualizzazione delle funzionalità di rete svolte da apparati di telecomunicazione fisici. Questi due concetti sono strettamente legati tra loro e possono comportare particolari vantaggi se applicati contemporaneamente, ma sono di per sè indipendenti. Software Defined Networking (SDN) è un’ architettura utilizzata per la realizzazione di reti di telecomunicazione nelle quali il piano di controllo della rete e quello del trasporto dei dati sono separati logicamente. La Network Function Virtualization (NFV) è il processo di virtualizzazione delle funzionalità di rete svolte da apparati di telecomunicazione fisici. Un ultimo aspetto da trattare riguarda la comunicazione del controller SDN di alto e basso livello. La comunicazione di alto livello, ovvero quella con i software applicativi è consentita grazie alle NBI (North-Bound Interfaces), mentre quella di basso livello, ovvero con i dispositivi hardware è consentita grazie alle SBI (South-Bound Interfaces). Queste due interfacce riescono a soddisfare le richieste del controller SDN grazie all' applicazione del paradigma Intent NBI, di tipo dichiarativo, non prescrittivo e indipendente dal fornitore.

Mestrado em Engenharia de Computadores e Telemática
Service Function Chaining, Virtual Network Functions e Cloud Computing são os conceitos chave para resolver (em “grande plano”) uma necessidade actual dos operadores de telecomunicações: a virtualização dos equipamentos na casa dos consumidores, particularmente o Home Gateway. Dentro deste contexto, o objetivo desta dissertação será providenciar as Funções Virtuais de Rede (tais como um vDHCP, Classificador de Tráfego e Shaper) assim como respectivas APIs necessárias para se atingir essa solução de “grande plano”. A solução utilizará tecnologias Open Source como OpenStack, OpenVSwitch e OpenDaylight (assim como contribuições anteriores do Instituto de Telecomunicações) para concretizar uma Prova-de-Conceito do Home Gateway virtual. Após o sucesso da primeira PdC iniciar-se-á a construção da próxima prova, delineando um caminho claro para trabalho futuro.
Service Function Chaining, Network Function Virtualization and Cloud Computing are the key concepts to solve (in “big-picture”) one of today’s operator’s needs: virtual Customer Premises Equipments, namely the virtualization of the Home Gateway. Within this realm, it will be the purpose of this dissertation to provide the required Virtual Network Functions (such as a vDHCP, Traffic Classifier and Traffic Shaper) as well as their respective APIs to build that “big-picture” solution. Open Source technologies such as OpenStack, OpenVSwitch and OpenDaylight (along with prior work from Instituto de Telecomunicações) will be used to make a working Proof-of-Concept of the Virtual Home Gateway. After the success of the first PoC, starts the construction of the next PoC and a path for future work is laid-down.

Les réseaux traditionnels reposent sur un grand nombre de fonctions réseaux très hétérogènes qui s'exécutent sur du matériel propriétaire déployé dans des boîtiers dédiés. Concevoir ces dispositifs spécifiques et les déployer est complexe, long et coûteux. De plus, comme les besoins des clients sont de plus en plus importants et hétérogènes, les fournisseurs de services sont contraints d'étendre ou de moderniser leur infrastructure régulièrement, ce qui augmente fortement les coûts d'investissement (CAPEX) et de maintenance (OPEX) de l'infrastructure. Ce paradigme traditionnel provoque une ossification du réseau et rend aussi plus complexe la gestion et la fourniture des fonctions réseau pour traiter les nouveaux cas d'utilisation. La virtualisation des fonctions réseau (NFV) est une solution prometteuse pour relever de tels défis en dissociant les fonctions réseau du matériel sous-jacent et en les implémentant en logiciel avec des fonctions réseau virtuelles (VNFs) capables de fonctionner avec du matériel non spécifique peu coûteux. Ces VNFs peuvent être organisés et chaînés dans un ordre prédéfini, formant des chaînes de Services (SFC) afin de fournir des services de bout-en-bout aux clients. Cependant, même si l'approche NFV comporte de nombreux avantages, il reste à résoudre des problèmes difficiles comme le placement des fonctions réseau demandées par les utilisateurs sur le réseau physique de manière à offrir le même niveau de résilience que si une infrastructure dédiée était utilisée, les machines standards étant moins fiables que les dispositifs réseau spécifiques. Ce problème devient encore plus difficile lorsque les demandes de service nécessitent des décisions de placement à la volée. Face à ces nouveaux défis, nous proposons de nouvelles solutions pour résoudre le problème du placement à la volée des VNFs tout en assurant la résilience des services instanciés face aux pannes physiques pouvant se produire dans différentes topologies de centres de données (DC). Bien qu'il existe des solutions de récupération, celles-ci nécessitent du temps pendant lequel les services affectés restent indisponibles. D'un autre côté, les décisions de placement intelligentes peuvent épargner le besoin de réagir aux pannes pouvant se produire dans les centres de données. Pour pallier ce problème, nous proposons tout d'abord une étude approfondie de la manière dont les choix de placement peuvent affecter la robustesse globale des services placés dans un centre de données. Sur la base de cette étude, nous proposons une solution déterministe applicable lorsque le fournisseur de services a une connaissance et un contrôle complets de l'infrastructure. Puis, nous passons de cette solution déterministe à une approche stochastique dans le cas où les SFCs sont demandées par des clients indépendamment du réseau physique du DC, où les utilisateurs n'ont qu'à fournir les SFC qu'ils veulent placer et le niveau de robustesse requis (e.g., les 5 neufs). Nous avons développé plusieurs algorithmes et les avons évaluées. Les résultats de nos simulations montrent l'efficacité de nos algorithmes et la faisabilité de nos propositions dans des topologies de centres de données à très grande échelle, ce qui rend leur utilisation possible dans un environnement de production. Toutes ces solutions proposées fonctionnent de manière efficace dans un environnement de confiance, comme les centres de données, avec la présence d’une autorité centrale qui contrôle toute l'infrastructure. Cependant, elles ne s'appliquent pas à des scénarios décentralisés comme c'est le cas lorsque différentes entreprises ont besoin de collaborer pour exécuter les applications de leurs clients. Nous étudions cette problématique dans le cadre des applications MapReduce exécutées en présence de nœuds byzantins et de nœuds rationnels et en l’absence de tiers de confiance
Traditional networks are based on an ever-growing variety of network functions that run on proprietary hardware devices called middleboxes. Designing these vendor-specific appliances and deploying them is very complex, costly and time-consuming. Moreover, with the ever-increasing and heterogeneous short-term services requirements, service providers have to scale up their physical infrastructure periodically, which results in high CAPEX and OPEX. This traditional paradigm leads to network ossification and high complexity in network management and services provisioning to address emerging use cases. Network Function Virtualization (NFV) has attracted notable attention as a promising paradigm to tackle such challenges by decoupling network functions from the underlying proprietary hardware and implementing them as software, named Virtual Network Functions (VNFs), able to work on inexpensive commodity hardware. These VNFs can be arranged and chained together in a predefined order, the so-called Service Function chaining (SFC), to provide end-to-end services. Despite all the benefits associated with the new paradigm, NFV comes with the challenge of how to place the functions of the users' requested services within the physical network while providing the same resiliency as if a dedicated infrastructure were used, given that commodity hardware is less reliable than the dedicated one. This problem becomes particularly challenging when service requests have to be fulfilled as soon as they arise (i.e., in an online manner). In light of these new challenges, we propose new solutions to tackle the problem of online SFC placement while ensuring the robustness of the placed services against physical failures in data-center (DC) topologies. Although recovery solutions exist, they still require time in which the impacted services will be unavailable while taking smart placement decisions can help in avoiding the need for reacting against simple network failures. First, we provide a comprehensive study on how the placement choices can affect the overall robustness of the placed services. Based on this study we propose a deterministic solution applicable when the service provider has full knowledge and control on the infrastructure. Thereafter, we move from this deterministic solution to a stochastic approach for the case where SFCs are requested by tenants oblivious to the physical DC network, where users only have to provide the SFC they want to place and the required availability level (e.g., 5 nines). We simulated several solutions and the evaluation results show the effectiveness of our algorithms and the feasibility of our propositions in very large scale data center topologies, which make it possible to use them in a productive environment. All these solutions work well in trusted environments with a central authority that controls the infrastructure. However, in some cases, many enterprises need to collaborate together in order to run tenants' application, e.g., MapReduce applications. In such a scenario, we move to a completely untrusted decentralized environment with no trust guarantees in the presence of not only byzantine nodes but also rational nodes. We considered the case of MapReduce applications in such an environment and present an adapted MapReduce framework called MARS, which is able to work correctly in such a context without the need of any trusted third party. Our simulations show that MARS grants the execution integrity in MapReduce linearly with the number of byzantine nodes in the system

O presente trabalho apresenta um modelo de aplicação de ferramentas de projeto integradas ao longo das fases de desenvolvimento de produto, neste caso, aplicadas na melhoria do produto suporte para fixação de cilindro de gás natural veicular. O foco do trabalho é apresentar a integração de ferramentas nas fases de Projeto Informacional, Projeto Conceitual e Projeto Detalhado do Processo de Desenvolvimento de Produtos. Entende-se por integração a escolha de ferramentas que permitam conduzir o fluxo de informação ao longo das fases de desenvolvimento de produtos, de tal forma que a informação de saída de uma ferramenta seja a informação de entrada da ferramenta subseqüente. As ferramentas integradas a partir da fase de Projeto Informacional foram a Pesquisas de Mercado Qualitativa e Quantitativa, com a finalidade de identificar as demandas dos clientes. As demandas dos clientes foram os dados de entrada da Matriz da Qualidade (Quality Function Deployment - QFD), resultando nos requisitos do produto e suas respectivas especificações-meta. A partir dos requisitos do produto, diferentes conceitos (configurações) foram gerados, apoiados pela Matriz Morfológica no Projeto Conceitual. Na seqüência utilizou-se a ferramenta de Projeto de Experimentos (Design of Experiments - DOE) para avaliar a estimativa de preço frente às possíveis configurações do produto. Com a Matriz de Pugh, alternativas de conceito de produto foram avaliadas possibilitando a escolha do melhor conceito de produto. No Projeto Detalhado, foi aplicada ferramenta de Análise dos Modos de Falha e seus Efeitos (Failure Mode and Effects Analysis - FMEA), utilizado de forma integrada com o QFD, para identificar as falhas atuais e potenciais e seus efeitos em sistemas e processo. Em função das demandas identificadas, foram definidas e implementadas melhorias no produto. Observou-se a adequabilidade destas ferramentas de projeto para aplicação de forma integrada, garantindo um fluxo contínuo de informações rastreáveis e que tendem a levar à uma reduzida chance de perdas ao longo do processo.
There are few examples in literature about the integration of project tools along the product development phases. The main research objective in thesis is to integrate some tools that facilitate the information flow along the product development phases, more specifically in Informational Project, Conceptual Project and Detailed Project phases. The product improvement “support for Vehicular Natural Gas” was the object of study in thesis. The main idea is that the information output from one tool is the input information of the subsequent tool. Starting from the Informational Project phase it was performed qualitative and quantitative market researches with the purpose of identifying the customers' demands for the studied product. The customers’ demands were the entrance data of the QFD (Quality Function Deployment) tool resulting in the product requirements and their respective specifications-goal. In Concept Project the product requirements were converted in functions and further different concepts were generated through the Morphologic Analysis. In the sequence, it was used the DOE (Design for experiments) tool to evaluate the estimate price to the possible products' configurations. The Pugh Matrix tool was used for concepts evaluation and choice. The FMEA (Failure Mode and Effects Analysis) tool integrated with QFD was useful for current and potential failures identification and impact analysis in the system and process. With the application of these five tools the users’ demands were identified and improvements to the product were performed. The chosen tools proved to be adequate for integration, assuring that a continuous trackable information flow was attained with presumable reduced information loss, along the Product Development Process phases.

碩士
國立交通大學
資訊科學與工程研究所
107
Over the last few years, network function virtualization (NFV) has been developing rapidly in both academia and industry since it promises flexible and scalable network management and orchestration. The European Telecommunications Standards Institute (ETSI) has designed NFV management and orchestration (NFV-MANO) architectural framework for the purpose of managing and orchestrating the network services and their corresponding virtualized network functions (VNFs). In the NFV-MANO, the NFV orchestrator (NFVO) manages the network services and coordinates with the VNF managers (VNFMs) which manage the lifecycle of VNFs. It is a challenging problem to determine the placement of VNFMs that keeps the operational cost down without violating the performance requirements. Existing centralized solution that suffers from scalability and privacy issues, in this paper, we leverage potential game theory to achieve distributed solutions to the VNFM placement problem (MPP). More importantly, our distributed solutions hold the property of self-adaptability. It can adapt the changes in the system like some VNFMs are faulty or the number of VNF instances varies. On the other hand, we also show that the game possesses a potential function and admits a Nash equilibrium (NE). Numerical results show the cost efficiency and adaptability of our approaches.

碩士
國立臺灣科技大學
資訊工程系
107
In traditional networks, the control plane and the data plane are bundled into one switch. The flow of packets are forwarded based on the rules that have been decided since switches were made by the manufacturers. The rules that in switches cannot be modified and it forward packets following the shortest path algorithm generally. Obviously, there are some disadvantages in traditional networks. Traditional networks cannot change the routing policy to encounter differnet situations. Thus, there is an emerging paradigm named Software-Defined Networking (SDN) that separate the control plane from the data plane. By breaking vertical integration, SDN separate the networks control logic from the underlying routers and switches, promoting (logical) centralization of network control, and introducing the ability to program the network. There is another promising technology named network function virtualization (NFV). NFV implements network functions (e.g., firewalls, intrusion detection systems (IDSs), deep packet inspection (DPI)) as software running in a virtual machine. In the past, network functions are typically made by dedicated hardware devices named middlebox which are very expensive and hard to manage. NFV reduce the cost of implementing network functions and provide a more flexible way to construct the Internet. Underpinned by the NFV technique, Software-Defined Networking (SDN) that separates the control plane from the data plane can be utilized to enable inexpensive and flexible implementation of network functions as software components running in Virtual Machines (VMs), rather than expensive and hard-to-manage hardware middleboxes. Therefore, routing algorithm for NFV enablement within SDN that minimum the operation cost or maximum the throughput may be useful in this new architecture.

碩士
國立中興大學
資訊科學與工程學系所
107
With new technological advances, application services have become more and more diversified. The applications of Augmented Reality (AR) have received great attention from academics and operators. However, the complex computing required for AR application services has caused service operators to face problems of poor user experience due to insufficient computing resources. Network function virtualization (NFV) enables operators to directly establish network functions on virtual machines, and can flexibly adjust the number of each virtual network function (VNF) according to users’ requirements. Thus, the system can reduce unnecessary waste of resources. In addition, we use multi-access edge computing (MEC) to provide computing resources. The edge server is close to the user and reduces transmission cost of the system. This paper proposes an MEC-based VNF placement and scheduling scheme for AR application. Considering the function topology of AR application, the compute-intensive application can provide good service quality for a large number of users within limited resources. The simulation presents that the proposed method can maintain good service quality as the number of user requests increases. Moreover, we use queueing theory to design a queueing model for the MEC-based VNF scheduling algorithm and use mathematical analysis to validate simulation results.

碩士
國立中正大學
通訊工程研究所
107
Network Function Virtualization (NFV)is a technology that implement traditional physical network devices into virtual machine placed in the server. The virtual machine(VM) with network function is called Virtual Network Function(VNF), users can specify a service chain formed by multiple VNFs in a specific order, this is called Service Chain(SC). If every time a user apply for a Service Chain in the data center and the manager create new VNFs for it this will cause too many VNFs in the environment and increase the management cost and the waste of resource in the server. Randomly placing the VNFs in the environment will cause the routing path length of Service Chain increase and the waste of network bandwidth. We implement a System Orchestrtor (SO). When getting a SC request from the tenant, manager only need to input the SC information, such as VNF type, the order of VNFs, and the bandwidth require of the SC, SO can automatally deploy VNFs in the OpenStack environment based on the CPU usage of VNF, sharing status of the VNF, CPU and RAM usage of server, and network staus. Plus SO will add SC routing entry on P4 switch.

碩士
國立交通大學
電機工程學系
105
Current Network Function Virtualization (NFV) with Virtualized Network Functions (VNFs) running as virtual machines on commodity servers enables flexibility to Service Function Chaining (SFC). Specific applications may require Quality of Service (QoS) on end-to-end latency. However, the processing delay and the queuing delay of VNFs varies with virtual resource configurations (vCPU and vMemory), as well as physical usage (traffic amount, CPU utilization). Moreover, packet delays are randomly distributed, instead of a fixed value. To accurately model the latency distribution of one VNF, a prediction method using random-forest regression is proposed. Evaluation results show that our method can precisely predict the latency distribution of the two sample VNFs with only 10% errors. On the basis of the model, a QoS-assured SFC deployment algorithm is also presented to guarantee end-to-end latency and bandwidth consumption of users. Experiments show that our algorithm enables high degree of scalability, and meanwhile maximizes user acceptance rates with 6% difference from the optimal solution from the mixed integer programming.

碩士
國立臺灣大學
電機工程學研究所
107
For satisfying low latency service requests from users, we allocate resources from MEC servers in mobile edge cloud to provide VNFs to the required services. Considering the scant resource in mobile edge cloud, we want to improve the resource utility. The term Follow Me Cloud (FMC) is widely used to state the problem of allocating VNF resources in clouds to users’ services while considering service migration if users are moving in the network. On the other hand, Network Function Consolidation (NFC) is a mechanism to share the underlying VM the VNF is embedded on, which saves the operation system baseline resource consumption of the VM. By consolidating VNF with nearby MECs that already exist the same service type VM, we can reduce the overall MEC capacity costs. However, user mobility affects the performance of NFC when solving the FMC problem, so we use a mobility prediction model to capture mobility pattern and use Deep Reinforcement Learning to learn the proper way to allocate resources in order to reduce costs. We proposed the model DeepPack, to optimize the FMC problem while combining the NFC mechanism. Finally, the system performance is discussed with the simulation results.

In this thesis various aspects of Quality of Experience (QoE) research are examined. The work is divided into three major blocks: QoE Assessment, QoE Monitoring, and VNF Performance Evaluation. First, prominent cloud applications such as Google Docs and a cloud-based photo album are explored. The QoE is characterized and the influence of packet loss and delay is studied. Afterwards, objective QoE monitoring for HTTP Adaptive Video Streaming (HAS) in the cloud is investigated. Additionally, by using a Virtual Network Function (VNF) for QoE monitoring in the cloud, the feasibility of an interworking of Network Function Virtualization (NFV) and cloud paradigm is evaluated. To this end, a VNF that exploits deep packet inspection technique was used to parse the video traffic. An algorithm is then designed accordingly to estimate video quality and QoE based on network and application layer parameters. To assess the accuracy of the estimation, the VNF is measured in different scenarios under different network QoS and the virtual environment of the cloud architecture. The insights show that the different geographical deployments of the VNF influence the accuracy of the video quality and QoE estimation. Various Service Function Chain (SFC) placement algorithms have been proposed and compared in the context of edge cloud networks. On the one hand, this research is aimed at cloud service providers by providing methods for evaluating QoE for cloud applications. On the other hand, network operators can learn the pitfalls and disadvantages of using the NFV paradigm for such a QoE monitoring mechanism
In dieser Arbeit werden verschiedene Aspekte von Quality of Experience (QoE) und QoE-Monitoring untersucht. Die Arbeit teilt sich in drei große Blöcke auf: QoE Assessment, QoE Monitoring und Leistungsuntersuchung einer VNF. Zunächst werden prominente Cloud-Anwendungen wie Google Docs und ein Cloud-basiertes Photoalbum untersucht. Die QoE wird charakterisiert und es wird der Einfluss von Paketverlust und Delay studiert. Danach wird das objektive QoE-Monitoring für HTTP Adaptive Video Streaming (HAS) in der Cloud untersucht. Durch die Verwendung einer virtuellen Netzwerkfunktion (Virtual Network Function, VNF) für die QoE-Überwachung in der Cloud wurde außerdem die Durchführbarkeit eines Zusammenwirkens von Netzwerkfunktionsvirtualisierung (NFV) und Cloud-Paradigma bewertet. Zu diesem Zweck wurde der VNF, die die Deep-Packet-Inspection-Technik benutzt, zum Parsen des Videoverkehrs verwendet. Im Anschluss wurde ein Algorithmus entworfen, um die Videoqualität und die QoE basierend auf Netzwerk- und Anwendungsschichtparametern zu schätzen. Um die Genauigkeit der Schätzung zu bewerten, wurde die VNF in verschiedenen Szenarien unter verschiedener Netzwerk-QoS und der virtuellen Umgebung der Cloud-Architektur gemessen. Die Erkenntnisse zeigen, dass die unterschiedlichen geografischen Implementierungen der VNF die Genauigkeit der Schätzung der Videoqualität und QoE beeinflussen. Es wurden verschiedene Platzierungsalgorithmen der Service Function Chain (SFC) vorgeschlagen und im Kontext von Edge-Cloud-Netzwerken verglichen. Diese Forschungsarbeit zielt zum einen auf Cloud-Service-Provider ab, indem ihnen Methoden zur Bewertung der QoE für Cloud-Anwendungen zur Verfügung gestellt werden. Auf der anderen Seite können die Netzwerkbetreiber die Fallstricke und Nachteile der Anwendung des NFV-Paradigmas für einen solchen QoE-Überwachungsmechanismus erlernen

碩士
國立中央大學
資訊工程學系
103
Traditional network architecture is facing a revolution. The Software-Defined Networking (SDN) and Network Functions Virtualization (NFV), two new network concepts have been proposed, network equipment manufacturers, telecom operators, IC design house, have invested a lot of research resources, participation in the development of specification. SDN decouples the control plane and data plane, through the Controller application for centralized network management. Currently OpenFlow which promote by Open Networking Foundation (ONF) is the mainstream SDN communication protocol and it as a communication of control plane and data plane. European Telecommunications Standards Institute (ETSI) established NFV Industry Specification Group (ISG) were NFV technology research and specification, aimed at all kinds of network components such as: routers, firewalls, load balancing and other network functions, from a specific hardware device pulled out, the use of virtualization technology, convert to Virtual Network Function (VNF) and through software approach, deployed in the NFV Infrastructure (NFVI). In this paper, according to the NFV Architecture Framework proposed by ETSI to build a Linct (Large-scale Intelligent NFV / SDN Cross -domain Testbed) on National Central University (NCU), National Cheng Kung University (NCKU) and National Center for High-performance Computing (NCHC) and design and implement NFV resource Orchestrator - Linct Orchestrator, to monitor resource utilization and system status from NFVI and VNF, provide VNF load balancing and high availability module. This paper proposed Vector-Based VNF Deployment Mechanism for NFVI Load Balance (VBVD) mechanism, this mechanism will be calculated based on each NFVI current resource utilization, to choose the most appropriate NFVI and deploy VNF on it, in order to achieve load balancing for all NFVI in testbed and optimize the use of resources and avoid resources overloading for single NFVI.

碩士
國立中正大學
通訊工程研究所
105
Network Function Virtualization (NFV) as a new policy enforcement and service provisioning paradigm is considered as a framework for handling VNF placement and orchestration in the network. Each incoming request as a sequence of Network Functions (NFs), called Service Chain (SC), is processed and the environment is optimally prepared for satisfying the request. The SC provisioning has some operational costs. Creating VNF for each VNF request increases the number of VNFs in an unpleasant manner that leads to the higher resource wastage, environmental complexity and management costs. Because of the improper placement of the VNFs for each SC, the bandwidth usage cost affects the performance of the network. For decreasing the VNF numbers and bandwidth usage costs in the network, we propose Central Orchestration System (COS) which integrates the benefits of OpenStack in the presence of SDN technology. Our proposed method, according to the user request and the current situation of the network, calculates the optimum VNF locations and the connecting path of the VNFs in order to minimize the bandwidth and number of VNF costs. The first experiment confirms the computation time of our optimization model in a 48-ary Fat tree network environment. In the second experiment the COS had the better performance in comparison with the other methods.