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Gokan, Khan Michel. "Performance Modelling and Simulation of Service Chains for Telecom Clouds." Licentiate thesis, Karlstads universitet, Institutionen för matematik och datavetenskap (from 2013), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-83687.
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New services and ever increasing traffic volumes require the next generation of mobile networks, e.g. 5G, to be much more flexible and scalable. The primary enabler for its flexibility is transforming network functions from proprietary hardware to software using modern virtualization technologies, paving the way of virtual network functions (VNF). Such VNFs can then be flexibly deployed on cloud data centers while traffic is routed along a chain of VNFs through software-defined networks. However, such flexibility comes with a new challenge of allocating efficient computational resources to each VNF and optimally placing them on a cluster. In this thesis, we argue that, to achieve an autonomous and efficient performance optimization method, a solid understanding of the underlying system, service chains, and upcoming traffic is required. We, therefore, conducted a series of focused studies to address the scalability and performance issues in three stages. We first introduce an automated profiling and benchmarking framework, named NFV-Inspector to measure and collect system KPIs as well as extract various insights from the system. Then, we propose systematic methods and algorithms for performance modelling and resource recommendation of cloud native network functions and evaluate them on a real 5G testbed. Finally, we design and implement a bottom-up performance simulator named PerfSim to approximate the performance of service chains based on the nodes’ performance models and user-defined scenarios.
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Behravesh, Rasoul <1988>. "Life-cycle management and placement of service function chains in MEC-enabled 5G networks." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amsdottorato.unibo.it/9732/1/Thesis.pdf.
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Recent advancements in mobile communication technology have led to the fifth generation of mobile cellular networks (5G), driven by the proliferation in data traffic demand, stringent latency requirements, and the desire for a fully connected world. This transformation calls for novel technology solutions such as Multi-access Edge Computing (MEC) and Network Function Virtualization (NFV) to satisfy service requirements while providing dynamic and instant service deployment. MEC and NFV are two principal and complementary enablers for 5G networks whose co-existence can lead to numerous benefits. Despite the numerous advantages MEC offers, physical resources at the edge are extremely scarce and require efficient utilization.
In this doctoral dissertation, we first attempt to optimize resource utilization at the network edge for the scenario of live video streaming. We specifically utilize the real-time Radio Access Network (RAN) information available at the MEC servers to develop a machine learning-based prediction solution and anticipate user requests. Consequently, Integer Linear Programming (ILP) models are used to prefetch/cache video contents from a centralized video server.
Regarding the advantages of NFV technology for the deployment of NFs, the second problem that this dissertation address is the proper association of the users to the gNBs along with efficient placement of SFCs on the substrate network. Our primary purpose is to find a proper embedding of the SFC in a hierarchical 5G network. The problem is formulated as a Mixed Integer Linear Programming (MILP) model, having the objective to minimize service provisioning cost, link utilization, and the effect of VNF migration on users' perceived quality of experience.
After rigorously analyzing the proposed SFC placement and considering mobile networks' dynamicity, our next goal is to develop an ILP-based model that minimizes the resource provisioning cost by dynamically embed and scale SFCs so that provisioning cost is minimized while user requirements are met.
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Farshin, Alireza. "Realizing Low-Latency Internet Services via Low-Level Optimization of NFV Service Chains : Every nanosecond counts!" Licentiate thesis, KTH, Network Systems Laboratory (NS Lab), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-249664.
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By virtue of the recent technological developments in cloud computing, more applications are deployed in a cloud. Among these modern cloud-based applications, some require bounded and predictable low-latency responses. However, the current cloud infrastructure is unsuitable as it cannot satisfy these requirements, due to many limitations in both hardware and software. This licentiate thesis describes attempts to reduce the latency of Internet services by carefully studying the currently available infrastructure, optimizing it, and improving its performance. The focus is to optimize the performance of network functions deployed on commodity hardware, known as network function virtualization (NFV). The performance of NFV is one of the major sources of latency for Internet services. The first contribution is related to optimizing the software. This project began by investigating the possibility of superoptimizing virtualized network functions(VNFs). This began with a literature review of available superoptimization techniques, then one of the state-of-the-art superoptimization tools was selected to analyze the crucial metrics affecting application performance. The result of our analysis demonstrated that having better cache metrics could potentially improve the performance of all applications. The second contribution of this thesis employs the results of the first part by taking a step toward optimizing cache performance of time-critical NFV service chains. By doing so, we reduced the tail latencies of such systems running at 100Gbps. This is an important achievement as it increases the probability of realizing bounded and predictable latency for Internet services.<br>Tack vare den senaste tekniska utvecklingen inom beräkningar i molnet(“cloud computing”) används allt fler tillämpningar i molnlösningar. Flera avdessa moderna molnbaserade tillämpningar kräver korta svarstider är låga ochatt dessa ska vara förutsägbara och ligga inom givna gränser. Den nuvarandemolninfrastrukturen är dock otillräcklig eftersom den inte kan uppfylla dessa krav,på grund av olika typer av begränsningar i både hårdvara och mjukvara. I denna licentiatavhandling beskrivs försök att minska fördröjningen iinternettjänster genom att noggrant studera den nuvarande tillgängligainfrastrukturen, optimera den och förbättra dess prestanda. Fokus ligger påatt optimera prestanda för nätverksfunktioner som realiseras med hjälp avstandardhårdvara, känt som nätverksfunktionsvirtualisering (NFV). Prestanda hosNFV är en av de viktigaste källorna till fördröjning i internettjänster. Det första bidraget är relaterat till att optimera mjukvaran. Detta projektbörjade med att undersöka möjligheten att “superoptimera” virtualiseradenätverksfunktioner (VNF). Detta inleddes med en litteraturöversikt av tillgängligasuperoptimeringstekniker, och sedan valdes ett av de toppmodernasuperoptimeringsverktygen för att analysera de viktiga mätvärden som påverkartillämpningssprestanda. Resultatet av vår analys visade att bättre cache-mätningar potentiellt skulle kunna förbättra prestanda för alla tillämpningar. Det andra bidraget i denna avhandling utnyttjar resultaten från den förstadelen genom att ta ett steg mot att optimera cache-prestanda för tidskritiskakedjor av NFV-tjänster. Genom att göra så reducerade vi de långa fördröjningarnahos sådana system som kördes vid 100 Gbps. Detta är en viktig bedrift eftersomdetta ökar sannolikheten för att uppnå en begränsad och förutsägbar fördrörninghos internettjänster.<br><p>QC 20190415</p><br>Time-Critical Clouds<br>ULTRA
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Hassan, Ahmed Mohamed Medhat Mohamed Ahmed [Verfasser], Thomas [Akademischer Betreuer] Magedanz, Thomas [Gutachter] Magedanz, Axel [Gutachter] Küpper, and Neco [Gutachter] Ventura. "Elastic and dynamic orchestration of service function chains for 5G networks / Ahmed Mohamed Medhat Mohamed Ahmed Hassan ; Gutachter: Thomas Magedanz, Axel Küpper, Neco Ventura ; Betreuer: Thomas Magedanz." Berlin : Technische Universität Berlin, 2017. http://d-nb.info/1156462711/34.
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Silvestro, Alessio [Verfasser], Xiaoming [Akademischer Betreuer] Fu, Xiaoming [Gutachter] Fu, et al. "Architectural Support for Implementing Service Function Chains in the Internet / Alessio Silvestro ; Gutachter: Xiaoming Fu, Jussi Kangasharju, Dieter Hogrefe, Fabian Schneider, Simon Pietro Romano, Mayutan Arumaithurai ; Betreuer: Xiaoming Fu." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://d-nb.info/1180026403/34.
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Subramanya, Tejas. "Autonomic Management and Orchestration Strategies in MEC-Enabled 5G Networks." Doctoral thesis, Università degli studi di Trento, 2021. http://hdl.handle.net/11572/320883.
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5G and beyond mobile network technology promises to deliver unprecedented ultra-low latency and high data rates, paving the way for many novel applications and services. Network Function Virtualization (NFV) and Multi-access Edge Computing (MEC) are two technologies expected to play a vital role in achieving ambitious Quality of Service requirements of such applications. While NFV provides flexibility by enabling network functions to be dynamically deployed and inter-connected to realize Service Function Chains (SFC), MEC brings the computing capability to the mobile network's edges, thus reducing latency and alleviating the transport network load. However, adequate mechanisms are needed to meet the dynamically changing network service demands (i.e., in single and multiple domains) and optimally utilize the network resources while ensuring that the end-to-end latency requirement of services is always satisfied. In this dissertation work, we break the problem into three separate stages and present the solutions for each one of them.Firstly, we apply Artificial Intelligence (AI) techniques to drive NFV resource orchestration in MEC-enabled 5G architectures for single and multi-domain scenarios. We propose three deep learning approaches to perform horizontal and vertical Virtual Network Function (VNF) auto-scaling: (i) Multilayer Perceptron (MLP) classification and regression (single-domain), (ii) Centralized Artificial Neural Network (ANN), centralized Long-Short Term Memory (LSTM) and centralized Convolutional Neural Network-LSTM (CNN-LSTM) (single-domain), and (iii) Federated ANN, federated LSTM and federated CNN-LSTM (multi-domain). We evaluate the performance of each of these deep learning models trained over a commercial network operator dataset and investigate the pros and cons of different approaches for VNF auto-scaling. For the first approach, our results show that both MLP classifier and MLP regressor models have strong predicting capability for auto-scaling. However, MLP regressor outperforms MLP classifier in terms of accuracy. For the second approach (one-step prediction), CNN-LSTM performs the best for the QoS-prioritized objective and LSTM performs the best for the cost-prioritized objective. For the second approach (multi-step prediction), the encoder-decoder CNN-LSTM model outperforms the encoder-decoder LSTM model for both QoS and Cost prioritized objectives. For the third approach, both federated LSTM and federated CNN-LSTM models perform equally better than the federated ANN model. It was also noted that in general federated learning approaches performs poorly compared to centralized learning approaches. Secondly, we employ Integer Linear Programming (ILP) techniques to formulate and solve a joint user association and SFC placement problem, where each SFC represents a service requested by a user with end-to-end latency and data rate requirements. We also develop a comprehensive end-to-end latency model considering radio delay, backhaul network delay and SFC processing delay for 5G mobile networks. We evaluated the proposed model using simulations based on real-operator network topology and real-world latency values. Our results show that the average end-to-end latency reduces significantly when SFCs are placed at the ME hosts according to their latency and data rate demands. Furthermore, we propose an heuristic algorithm to address the issue of scalability in ILP, that can solve the above association/mapping problem in seconds rather than hours.Finally, we introduce lightMEC - a lightweight MEC platform for deploying mobile edge computing functionalities which allows hosting of low-latency and bandwidth-intensive applications at the network edge. Measurements conducted over a real-life test demonstrated that lightMEC could actually support practical MEC applications without requiring any change to existing mobile network nodes' functionality in the access and core network segments. The significant benefits of adopting the proposed architecture are analyzed based on a proof-of-concept demonstration of the content caching use case. Furthermore, we introduce the AI-driven Kubernetes orchestration prototype that we implemented by leveraging the lightMEC platform and assess the performance of the proposed deep learning models (from stage 1) in an experimental setup. The prototype evaluations confirm the simulation results achieved in stage 1 of the thesis.
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Abreu, Pollyanna Silva. "Desenvolvimento da voz do cliente no desdobramento da função qualidade (QFD) = aplicação em projetos de cadeira de rodas." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264360.
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Orientador: Franco Giuseppe Dedini<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica<br>Made available in DSpace on 2018-08-17T05:45:09Z (GMT). No. of bitstreams: 1
Abreu_PollyannaSilva_M.pdf: 3581814 bytes, checksum: e1e25ece993ce9c23f6bbc11ec80b9f8 (MD5)
Previous issue date: 2010<br>Resumo: Neste trabalho buscou-se a utilização de instrumentos, técnicas e procedimentos da Psicologia, para auxiliar a tradução das necessidades básicas de clientes em uma forma estruturada, para o levantamento da Voz do Cliente, a fim de auxiliar na aplicação do método Desdobramento da Função Qualidade (QFD). A pesquisa foi realizada com usuários de cadeira de rodas e, por meio de questionários abertos e fechados, e análises qualitativas e quantitativas dos dados obtidos, foram levantadas as principais necessidades dos cadeirantes em relação à cadeira de rodas. As necessidades levantadas foram divididas em parâmetros, traduzidas em requisitos de engenharia e inseridas na Matriz I (Casa da Qualidade) do QFD. Os processos adotados são sugeridos para equipes com profissionais de diversas áreas, como metodologia válida, para levantamento da Voz do Cliente. A Matriz construída possibilitará estabelecer alguns requisitos para soluções possíveis de projeto de cadeira de rodas<br>Abstract: This work aimed to utilize instruments, techniques and procedures of the psychology science to help in the translation the basic necessities of the clients in a well arranged form, known as client voice, in order to aid in the application of the Quality Function Deployment(QFD). The research was carried out with Wheel chair users and utilizing both open and closed questionnaires and both qualitative and quantitative analysis of the obtained data, the main client necessities was raised in regard to the Wheel chairs. The necessities raised was divided in parameters which were translated in requisites of engineering and then inserted in the Matrix (House of the Quality) of the QFD. The processes taken as basis are suggested to teams with Professionals from several areas, as a valid methodology to survey the client voice. The generated Matrix will enable to establish some requisite to possible solutions of wheel chairs projects<br>Mestrado<br>Mecanica dos Sólidos e Projeto Mecanico<br>Mestre em Engenharia Mecânica
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Visser, Riaan. "Operational-cost optimisation and cost management in the sourcing and supply chain : a conceptual framework for a medium-sized service company without a central procurement function." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/997.
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Thesis (MBA (Business Management))--Stellenbosch University, 2009.<br>ENGLISH ABSTRACT: A typical medium-sized service company in South Africa faces definite challenges and misses
opportunities in optimising and managing its operational expenses in its sourcing and supply
chain. Medium-sized companies generally do not have the benefit of sophisticated in-house
procurement divisions and extensive buying power but they still have to optimise their
expenses in order to ensure maximum profitability and business longevity.
The study addresses these challenges and opportunities by developing and proposing a
framework for a typical medium-sized service company that does not have a central
procurement function related to the cost optimisation and management of the identified
sourcing and supply-chain elements.
The research process entails the development of a conceptual framework developed from
literature analysis and a representational practical environment as well as the testing,
reviewing and validating of the test implementation of the framework. The results flowing
from the testing and implementation of the framework are excluded from the research project.
The results are displayed in the form of a summary of specific relevant information around
each framework element as well as a conceptual framework. Recommendations are made in
relation to the implementation and practical adaptation of the framework.
It is concluded that a medium-sized service company can successfully optimise and manage
its costs in the sourcing and supply-chain elements in the absence of a central procurement
function. This requires the effective implementation of the developed framework, which was
adapted from sophisticated larger companies. Implementation and the measurement process
need to be driven or, preferably, conducted by the medium-sized company owner or
management. Buy-in of the framework and the processes around it needs to be obtained from
employees, suppliers and other stakeholders.<br>AFRIKAANSE OPSOMMING: ’n Tipiese mediumgrootte diensverskaffingsonderneming in Suid-Afrika staar spesifieke
uitdagings in die gesig en ontbeer geleenthede met betrekking tot die optimalisering en
bestuur van die bedryfsuitgawes in sy aankoop- en verskaffingsketting. Mediumgrootte
ondernemings beskik in die algemeen nie oor die voordeel van ’n gesofistikeerde interne
aankoopafdeling en groot aankoopkrag nie, maar hierdie ondernemings moet nog steeds hulle
koste-uitgawes optimaliseer in die nastreef van maksimale wins en besigheidsukses.
Die navorsingstudie neem hierdie uitdagings en geleenthede onder die loep deur die
ontwikkeling en aanbeveling van ’n raamwerk vir ’n tipiese mediumgrootte
diensverskaffingsonderneming wat nie oor ’n sentrale interne aankoopafdeling beskik nie. Die
raamwerk is gebaseer op koste-optimalisering en -bestuur van die geïdentifiseerde aankoop- en verskaffingskettingelemente.
Die navorsingsproses behels die ontwikkeling van ’n konseptuele raamwerk deur
literatuuranalise en ’n verteenwoordigende praktiese omgewing, sowel as die toetsing,
hersiening en geldigverklaring van die raamwerk tydens die toets-implementering daarvan in
die praktiese omgewing. Die resultate van die toets en implementering van die raamwerk
vorm nie deel van hierdie studie nie.
Die navorsingsresultate word ten toon gestel in die vorm van ’n opsomming van die relevante
raamwerkelemente sowel as ’n ontwikkelde raamwerk. Aanbevelings ten opsigte van die
implementering en praktiese aanpassing van die raamwerk word dan gemaak.
Die gevolgtrekking word gemaak dat ’n mediumgrootte diensverskaffingsonderneming wel in
die afwesigheid van ’n sentrale interne aankoopafdeling sy kostes in die aankoop- en
verskaffingsketting suksesvol kan optimaliseer en bestuur. Dit kan gedoen word deur die
doeltreffende implementering en aanwending van die ontwikkelde raamwerk wat vanaf groter
ondernemings aangepas is. Die raamwerk se implementering- en metingsproses moet deur die
eienaar of bestuur van die mediumgrootte onderneming gelei, of verkieslik uitgevoer, word.
Die werknemers, verskaffers en ander belanghebbendes se ondersteuning vir die raamwerk en
gepaardgaande prosesse is baie belangrik vir die implementering en sukses van die raamwerk.
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Tröger, Ralph. "Supply Chain Event Management – Bedarf, Systemarchitektur und Nutzen aus Perspektive fokaler Unternehmen der Modeindustrie." Doctoral thesis, Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-155014.
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Supply Chain Event Management (SCEM) bezeichnet eine Teildisziplin des Supply Chain Management und ist für Unternehmen ein Ansatzpunkt, durch frühzeitige Reaktion auf kritische Ausnahmeereignisse in der Wertschöpfungskette Logistikleistung und -kosten zu optimieren.
Durch Rahmenbedingungen wie bspw. globale Logistikstrukturen, eine hohe Artikelvielfalt und volatile Geschäftsbeziehungen zählt die Modeindustrie zu den Branchen, die für kritische Störereignisse besonders anfällig ist. In diesem Sinne untersucht die vorliegende Dissertation nach einer Beleuchtung der wesentlichen Grundlagen zunächst, inwiefern es in der Modeindustrie tatsächlich einen Bedarf an SCEM-Systemen gibt.
Anknüpfend daran zeigt sie nach einer Darstellung bisheriger SCEM-Architekturkonzepte Gestaltungsmöglichkeiten für eine Systemarchitektur auf, die auf den Designprinzipien der Serviceorientierung beruht. In diesem Rahmen erfolgt u. a. auch die Identifikation SCEM-relevanter Business Services. Die Vorzüge einer serviceorientierten Gestaltung werden detailliert anhand der EPCIS (EPC Information Services)-Spezifikation illustriert.
Abgerundet wird die Arbeit durch eine Betrachtung der Nutzenpotenziale von SCEM-Systemen. Nach einer Darstellung von Ansätzen, welche zur Nutzenbestimmung infrage kommen, wird der Nutzen anhand eines Praxisbeispiels aufgezeigt und fließt zusammen mit den Ergebnissen einer Literaturrecherche in eine Konsolidierung von SCEM-Nutzeffekten. Hierbei wird auch beleuchtet, welche zusätzlichen Vorteile sich für Unternehmen durch eine serviceorientierte Architekturgestaltung bieten.
In der Schlussbetrachtung werden die wesentlichen Erkenntnisse der Arbeit zusammengefasst und in einem Ausblick sowohl beleuchtet, welche Relevanz die Ergebnisse der Arbeit für die Bewältigung künftiger Herausforderungen innehaben als auch welche Anknüpfungspunkte sich für anschließende Forschungsarbeiten ergeben.
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Silvestro, Alessio. "Architectural Support for Implementing Service Function Chains in the Internet." Doctoral thesis, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E5B4-7.
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Lei, Tsung-Han, and 雷宗翰. "Deploying QoS-assured Service Function Chains with Stochastic Prediction Models on VNF Latency." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/29ckq2.
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碩士<br>國立交通大學<br>電機工程學系<br>105<br>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.
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WANG, YUN, and 王云. "Adaptive Placement and Routing for Service Function Chains with Deadlines in Software-Defined Networks." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/8zw594.
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碩士<br>國立臺灣科技大學<br>資訊工程系<br>106<br>Software-defined network(SDN) is shifting data communication in network toward more centralized control. The controller manages all necessary information and decides the transit path through commands. Middleboxes such as firewalls, decryptors, load balancers, etc., are functional hardware devices that are indispensable in the cloud and in corporate networks, but are expensive and difficult to maintain.
The availability of virtual machines enables dynamic placement of virtual network functions(VNFs) on demand, it can reduce a large number of manual configuration processes, introduce flexibility, and increase deployment efficiency. Service requirements may need more than one VNF. Instead, it may need to traverse a set of sequential functional services called Service Function Chain (SFC). For example: first through the firewall, then through the encryption device, and finally through the decryption device, if these functional services are unordered, it will affect the correctness of the entire service requirements.
A key challenge is to efficiently route service function chains and place processing functions in a network under operational constraints. We must overcome two challenges: (1) determining a flow path that traverses suitable processing nodes in the correct order to meet the requirements of a given service chain, and (2) considering network load and other dynamic characteristics when routing through existing VNFs.
We present a method to solve the node-constrained service chain routing problem in a software-defined network. The main idea is to transform the network representation to a layered graph that considers processing steps and allows the use of conventional shortest path algorithms, such as Dijkstra’s algorithm, to solve the problem. We are not only pursuing the high efficiency of acceptance ratio, but also taking into account the execution time of the algorithm.
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Kulkarni, Sameer G. "Resource Management for Efficient, Scalable and Resilient Network Function Chains." Doctoral thesis, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E477-8.
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Chou, Hsin-Yao, and 周新堯. "SDN-based Network Resource Management with Service Function Chain." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/qrnak9.
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碩士<br>國立中央大學<br>資訊工程學系<br>103<br>In recent years, as growth of the cloud computing technology, more demand for network resources allocation and management of value-added services are appeared. The new concept of network service architecture, Service Function Chain (SFC), has been proposed. The specification of various vendor equipments is unique, prompts the traditional network to change. The purpose of Software-Defined Network (SDN) is to change the physical, complex network into a virtual, programmable and open network architecture. OpenFlow protocol is the most common technology for SDN architecture. The Network management can be more flexible by the centralized and programable property of OpenFlow. VLAN and OpenFlow based Service Function Chain (VOFSFC) and services deployment mechanism are proposed to improve the flexibility of the network service deployment and reduce the consumption of network resources.
VOFSFC use the virtual LAN (VLAN) technology to develop VLAN of Path adoption mechanism. It can identify different requirements of network traffic, steer/deliver packets to service functions and record information of the traffic. In addition, consider the placement of service functions, develop and propose GARCH and K-Means Service Function Placement (GKMSFP) mechanism to cluster and deploy service functions for reduce the load of network resources. The results shows the proposed VOPSFC system can provide high elasticity and flexibility for the network management, and the proposed GKMSFP mechanism can reduce 45.6% network resource consumption from the general situation which without cluster mechanism. It shows that mechanisms can reduce the traffic load of network in the SFC system.
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HUNG, CHONG-YOU, and 洪崇祐. "Performance Study of Service Function Chain with SGX-based Containers." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/76jxz9.
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碩士<br>國立中正大學<br>資訊工程研究所<br>107<br>Network function virtualization (NFV) is a new architecture that implements network functions in a virtialized environment. However, the platform for deploying network functions may be insecure. To eliminate the threat, network functions can be deployed with a trusted execution environment (TEE) mechanism such as Intel Software Guard Extension (SGX) in a secure region called enclave. In existing studies, all the network functions in a service chain are deployed in one enclave, but the enclave size is limited (up to 128MB in our investigation). In addition, the network functions need to be re-implemented from scratch to meet the requirements. In this work, we propose an approach, a service function chain with SGX-based containers, and study the performance issues on it. We deploy the network functions in several situations: on the same host, in the same container or on different hosts. We estimate the performance of packet transmission between the network functions in the same container with the shared memory mechanism (emulated by RAMdisk). In the other situations, the packets are transmitted via a switch and/or the virtual network interface controller (NIC). We also build two open-source network functions in SGX-based containers with few modifications for demonstration. In the experiments, we evaluate our system and find the throughput in shared memory can be as high as 400MB/s in packet transmission. We also find the encryption operation (AES in our experiments) and the receiving buffer size also have an impact on the throughput.
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Hsiao, Chung-Che, and 蕭崇哲. "Placement of Virtual Network Functions Using the Relation of Virtual Network Functions in Service Chains." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/87018831856926973824.
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碩士<br>國立清華大學<br>資訊工程學系<br>104<br>Network function virtualization (NFV) has changed the traditional usage of network functions from hardware appliances to software implementation. Placement of virtual network functions (VNFs) has become a fundamental problem in NFV. In this study, relation in VNFs, including dependency and changes of flow size, would be important factors in placement of VNFs onto virtual machines on servers. Metric embedding is adopted to combine the relation of VNFs and virtual machines on network servers. The structures shown in service chains are seized by embedding algorithm and thus reflect the result on placement of VNFs on the network. In the simulation section, the proposed technique is evaluated and performs well in test cases, showing that the proposed technique gives a fine solution to VNF placement problem.
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WANG, YU-REN, and 王昱人. "A load balance scheme by using service function chain of Opendaylight." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/swzujw.
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碩士<br>國立宜蘭大學<br>資訊工程學系碩士班<br>105<br>In recent years, mobile communication technology continues to explode the progress of the relative, the network management costs are growing, because the network needs to configure a lot of settings, such as: Route, VLAN (Virtual Local Area Network), QoS (Quality Of Service), STP (Spanning Tree Protocol) and LACP (Link Aggregation Control Protocol), etc., in a large network, because the traditional network of each node settings are rigid configuration, there is no way to achieve the global vision , Resulting in network administrators from time to time need to change these configurations, for example, whenever the New Year, the crowd brought huge amounts of information poured into, causing some switches overload and collapse.
SDN (Software-defined networking) is a new concept of network architecture, the main purpose is to network Flexibility, Manageability, Scalability, SDN is the biggest feature of the traditional network is divided into the control layer (Control Plane) and the data layer (Data Plane), the data forwarding decision by a single or multiple Controller to deal with, as long as the control layer and the data layer through the same open protocol OpenFlow communication, it is no longer rigidly adhere to the hardware label or model, the administrator or programmer can write software to easily achieve load balancing, so the appearance of the SDN improved Traditional networks can only be partially optimized and can not be fully configured shortcomings.
Considering the network packet of the various forwarding are bundled behind a number of network services, so we think that the use of SDN project Service Function Chain architecture so that the data can be flexible to do the forwarding action, select Service Function Chain is different from the use of flow table , the flow can also be real-time conversion when the traffic generated , even when the user made a different request, but also Automatically redirect packets to the desired service, in order to achieve the balance of traffic mechanism, the use of Network Service Header attached to the data, so that the data can be indicated by the Network Service Header to go through the node, the experimental structure of this study based on an physical machine simulation of eight virtual machines, through the design of the greedy algorithm based on the service function chain to add and modify the direction and order of the various services forward, after the experimental results, the use of this method can effectively relieve traffic in high-density environment caused by congestion problems.
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Tseng, Huai-En, and 曾懷恩. "The Low Latency Service Function Chain with SR-I/OV in Software Defined Network." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/362zzr.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>資訊工程系<br>106<br>Due to swift Internet technology and computer hardware development in recent years, the demands of network functions are rising. Compared to hardware-based network services, it is faster and more flexible to virtualize the network services and a flows may be processed by multiple network services as a Service Function Chain (SFC). Using Software Defined Network (SDN) is highly popular in the world because it can reduce deployment cost and time. However, the performance of Network Function Virtualiza- tion will be troubled by some congenital drawbacks. For instance, Network Function Virtualization usually suffers from I/O latency because it causes lots of interrupts that decreases CPU utilization. Although this can be solved somehow such as using SR-I/OV network card to reduce the system interrupts, the methods are still not perfect because it is not compatible with existing Software Defined Network system. For example, we often runs OpenvSwitch, an OpenFlow virtual switch supporting Software Defined Network, in general purpose server’s host OS to manage all the network packets forwarded to Virtualized Network Functions (VNFs). However, with OpenvSwitch, network packets must bypass host OS to guest OS when we use SR-I/OV network card. We will lose the benefit of SR-I/OV to enable SDN by using OpenvSwitch. Therefore, we propose an integrated architecture from a wider perspective in system design to overcome main defects described above. We modify appropriate components in SR-I/OV driver and OpenvSwitch to make Service Function Chain constructed by Virtualized Network Functions perform better and compatible with Software Defined Network environment.
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Feng, Chih-Chun, and 馮志鈞. "The Study on the Function Needs of Order Self Service for Chain Fast Food Restaurants." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/87630468046944851537.
Full textAbstract:
碩士<br>輔仁大學<br>資訊管理學系<br>101<br>The purpose of this study is to understand the consumers’ acceptance over
self-order service and the key function needs. Hopefully the result of this study
would furnish the chain fast food restaurants with a good reference
regarding to offering self-service.
Based on Technology Acceptance Model (TAM), Direct Benefit and
Deferred Benefit are adopted as external variables for Perceived
Usefulness and User Interface and Information Content are adopted
as external variables for Perceived Ease of Use.
Totally 130 responses were collected via an internet based questionnaire.
Among these responses, 109 responses are valid. Regression and Partial
Least Squares (PLS) were used to analyze the responses collected.
According to the responses, Deferred Benefit is positively related
to Direct Benefit and Direct Benefit is positively related to
Perceived Usefulness. Information Content is positively related to
User Interface and User Interface is positively related to Perceived Ease of Use.
Comparing the results with TAM, this study found that Intention to Use
is more significantly positively related to Perceived Ease of
Use than to Perceived Usefulness.
This study also found that Direct Benefit, such as discount, and User Interface,
such as provide content for the latest order, are very important for consumers.
The results provide the chain fast food restaurants a useful reference for providing self-service.
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Hsieh, Shun-Yu, and 謝舜宇. "Study of Service Function Chain Resource Management in Cloud Platform based on SDN and NFV." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/un5ehs.
Full textAbstract:
碩士<br>國立中央大學<br>資訊工程學系<br>105<br>近年來雲端計算的技術興起，越來越多的服務功能被開發出來，因此有了新的網路服務技術出現，服務功能鏈（Service Function Chain），有了這個技術，就可以佈署更加彈性的服務功能，不必限制於實體場景。軟體定義網路（Software Defined Network），為集中式的網路架構，目的將網路管理變得更加彈性且可程式化，減輕網路管理員的負擔。網路功能虛擬化（Network Function Virtualization）把原本需要特定硬體的網路功能分離出來，用軟體的方式實作，網路功能不再受限於硬體設備商。由於如何達成服務功能鏈的方式尚未成為標準，本論文結合軟體定義網路以及網路功能虛擬化這兩個技術實作出服務功能鏈平台。
本論文除了實作出管理平台還提出了資源管理的方式，有負責high availability的share和recovery機制，有負責提升服務功能使用率的merge機制，以及相對應產生的separate機制，還有應付大量流量的auto-scaling機制scale up和scale down機制。並提出一個演算法STSFCM（Stable Time Service Function Chain Management）用來決定上述六項機制要在何時啟動，在auto-scaling的部分加上時間的因素，使得在穩定使用率的狀態可以更好的利用VNF的資源。
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Chang, Ching-Ming, and 張景銘. "Using Quality Function Deployment into Study The Service Quality of Chain Stores– A Case Study of President Chain Store Corporation." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/96828805431448584685.
Full textAbstract:
碩士<br>大葉大學<br>事業經營研究所碩士在職專班<br>96<br>This research as 7-11 as research object, take advantage of Quality Function Deployment systematize inquire into 7-11 quality of service and quality of technology, questionnaire survey object as go pass 7-11 do shop consumer. Research framework refer PZB quality of service's mode, and refer Dabbolkar(1996) bring up de quality of service's measuring watch Retail Service Quality Scale(RSQS) come up to relative to document, again depend on chain stores characteristic, increase or curtail ask, analyze as questionaire project. Finding by SPSS calculate behind, as factor analysis establish 7-11 quality of service evaluate mode can divide into entity's image, credibility, personnel interaction, problem settle, shop's policy, price of article wait for six construct, permeate each quality of service construct element boot Quality Function Deployment, will consumer need de serve quality requirement transform for 7-11 quality's technology request, at last integrate analyze result hear of 7-11 front ten important quality's technologies ameliorate project for: Attitude of service, at scene handling capacity, personnel education and training, check system, master market's ability, manpower preparation, advertisement filtrate ability, enterprise's brand's image, return goods disposal, prompt consuming power. This findings will can supply 7-11 proceed what positional and quality of service administer's referrence.
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Lin, Heng-Te, and 林恆德. "Taiwan multi-functional digit machine industry service strategy study - Value chain view." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/53986854331600936742.
Full textAbstract:
碩士<br>輔仁大學<br>管理學研究所<br>93<br>This research aims at discussing multi-functional digit copier service tactics with the theory view of the value chain, how to weigh the value chain to manage and serve the behavior that the tactics carry out. Because information science and technology improve, cause market structure is it change to produce, and photogravure press already from imitate industry era develop into multi-functional several machine type attitude of equipment, having reduced information un-symmetry by a wide margin even more, the standard degree of merger of making the products improve is promoted day by day, and is moved into the plural goal by the difference of functions of the traditional product in the market competition factor, such as low cost leader, speed, elasticity and customer service demand etc., these changes influence the industrial structure and value chain to make up to some extent differently directly, key that it is important to survive for it.
Reason this of research changes the researcher to industry's experience of the photogravure press in information IT industry of the computer, use the value chain to manage meaning, use and combine the products of the industry of the photogravure press with information science and technology mainly, offer demand association and choice produced differently to customers. Guide and serve the manufacturer and use the value chain idea, reach and coordinate and divide the work, obtain complementary resources in industry's value chain in order to give play to serving the manufacturer, value chain formed of cooperation with close industry, area, even competitor, analyzes that the value chain innovates the management opinion chained with the value chain.
This thinking put forward of research, the expectation can help enterprises to improve innovation ability, increase the competition advantage, meet customer's demand or the service tactics to demand. Even there are less resources, is counting technical application and deriving product mix, under very diligent range, increase the valuable peripheral technological innovation, create and have competition advantage and key ability, make the value chain managed and applied to develop in industry. And analyze the service tactics meaning that this industry promote the competition advantage, support the application analyzing, on applying multi-functional digit copier industries to Taiwan and service strategy.
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Shih-Yuan, Wang, and 王士元. "Research of Quality Function Deployment for Practical Application - A Case Study of Service Quality of A Chain Convenient Store in North Region." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/34342135288492194527.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>管理技術研究所<br>86<br>Under the competitive situation on chain convenient stores, understanding and satisfying customer''s requirements is the key point to win the consumption of the market among the enterprises. However, making use of finite resources to obtain the greatest customer satisfaction needs much effort to take research. This research adopts quality function deployment (QFD) to help the enterprises find the most effective service quality improvement strategy and provide an objective method to evaluate. It makes customer requirements and quality improvement skills combined more rigorously. It also consults the bright and dull competitive situation to improve the effect and the practicality of the service quality improvement strategy. Through the intermediary of quality deployment, skill deployment, service orientation, strategy arrangement and house of quality (HOQ) which have systematization implementation procedures to present the evaluation of the process and the result, this research provides the proprietors an improvement tool which is easy to use and effective to substitute subjective consciousness evaluation method formerly. Hence, it can meet customer''s requirements more quickly and effectively. According to QFD changes, 21 items on the service quality of the chain convenient store transfers to 32 items of the quality improvement skill; this research generates results from the evaluation of HOQ by choosing the following priority of service quality improvement strategy: competition strategy, self-diagnose and achievement evaluation, point of sale system design and application, franchise chain management, race encouragement of track record, voluntary chain management, and strategy management of running stores.
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El-Khatib, Mayar. "Highway Development Decision-Making Under Uncertainty: Analysis, Critique and Advancement." Thesis, 2010. http://hdl.handle.net/10012/5741.
Full textAbstract:
While decision-making under uncertainty is a major universal problem, its implications in the field of transportation systems are especially enormous; where the benefits of right decisions are tremendous, the consequences of wrong ones are potentially disastrous.
In the realm of highway systems, decisions related to the highway configuration (number of lanes, right of way, etc.) need to incorporate both the traffic demand and land price uncertainties. In the literature, these uncertainties have generally been modeled using the Geometric Brownian Motion (GBM) process, which has been used extensively in modeling many other real life phenomena. But few scholars, including those who used the GBM in highway configuration decisions, have offered any rigorous justification for the use of this model.
This thesis attempts to offer a detailed analysis of various aspects of transportation systems in relation to decision-making. It reveals some general insights as well as a new concept that extends the notion of opportunity cost to situations where wrong decisions could be made. Claiming deficiency of the GBM model, it also introduces a new formulation that utilizes a large and flexible parametric family of jump models (i.e., Lévy processes). To validate this claim, data related to traffic demand and land prices were collected and analyzed to reveal that their distributions, heavy-tailed and asymmetric, do not match well with the GBM model. As a remedy, this research used the Merton, Kou, and negative inverse Gaussian Lévy processes as possible alternatives.
Though the results show indifference in relation to final decisions among the models, mathematically, they improve the precision of uncertainty models and the decision-making process. This furthers the quest for optimality in highway projects and beyond.