The information on the volume of traffic flowing between all possible origin and destination pairs in an IP network during a given period of time is generally referred to as traffic matrix (TM). This information, which is very important for various traffic engineering tasks, is very costly and difficult to obtain on large operational IP network, consequently it is often inferred from readily available link load measurements. In this thesis, we evaluated 5 TM estimation techniques, namely Tomogravity (TG), Entropy Maximization (EM), Quadratic Programming (QP), Linear Programming (LP) and Neural Network (NN) with gravity and worst-case bound (WCB) initial estimates. We found that the EM technique performed best, consistently, in most of our simulations and that the gravity model yielded better initial estimates than the WCB model. A hybrid of these techniques did not result in considerable decrease in estimation errors. We, however, achieved most significant reduction in errors by combining iterative proportionally-fitted estimates with the EM technique. Therefore, we propose this technique as a viable approach for estimating the traffic matrix of large-scale IP networks.

本論文著眼於All-IP網路中的預算分配。我們定義網路的服務品質只與各使用者使用網路頻寬的要求有關，提出一種使管理者能以統計上百分比來估計網路服務品質的方法。這個方法包含路徑選擇以及頻寬分配二個階段。為了展現這種方法的可行性，我們列舉一些數據來分別比較以最大滿意度和最小成本為目標的不同分配結果，作為使用這個方法的參考。 / In this thesis, we focus on budget allocation for All-IP networks. We propose a method which assists managers to estimate the quality of service on networks. The quality of service on networks is defined by satisfaction functions that are simply written in terms of bandwidth required by the users on the network. We present a two-phase approach which includes a path se-lection and a scheme for bandwidth allocation. In order to illustrate an easy implementation of this approach, we also develop the Maximum Satisfaction Method and the Minimum Cost Method. Numerical examples are given to show the effectiveness of our approach.

Este trabalho apresenta uma proposta de solução para compensar o atraso variável, característico de redes IP. O preditor de Smith é tradicionalmente usado para compensar atrasos, mas no caso deste tipo de rede um fator importante que pode degradar o controle do sistema são as grandes variações nos atrasos sofridos pelas mensagens. Para tratar este problema, este trabalho baseia-se na criação de uma estrutura de dados de armazenamento para a saída do preditor de Smith, possibilitando a comparação do valor de saída da planta com o valor adequado guardado na estrutura. Para determinação do valor correspondente, este está associado a um índice calculado com o tempo de roundtrip obtido de informações dos pacotes de dados proveniente da planta. Para se chegar a tal solução, foi analisada nas primeiras seções a influência do atraso em malhas de controle e posteriormente um estudo do estado da arte para tipos de controle sobre redes IP. Ao final é apresentada uma análise experimental, demonstrando resultados promissores da aplicação desta proposta. / This work presents a solution to compensate the varying delay, characteristic of IP networks. The Smith predictor is traditionally used to compensate delays but in this type of networks an other important factor that can destabilize the system is the large jitter of the delay. In order to solve this problem, the solution presented here is based on a data structure to save the output from the model of the plant used by the Smith predictor, that make possible to compare the output from the plant with the corresponding value in the structure. In order to take the correspondent value, it is associated to an index which is calculated with the roundtrip obtained from the informations in the packet arrived from the plant. In order to formulate this solution, it was analised in the first sections the influence of the delay in control systems and then a study of the state of art of the control systems over IP networks. At the end, an experimental analise to demonstrate the good result of the application of this solution is presented.

Este trabalho apresenta uma proposta de solução para compensar o atraso variável, característico de redes IP. O preditor de Smith é tradicionalmente usado para compensar atrasos, mas no caso deste tipo de rede um fator importante que pode degradar o controle do sistema são as grandes variações nos atrasos sofridos pelas mensagens. Para tratar este problema, este trabalho baseia-se na criação de uma estrutura de dados de armazenamento para a saída do preditor de Smith, possibilitando a comparação do valor de saída da planta com o valor adequado guardado na estrutura. Para determinação do valor correspondente, este está associado a um índice calculado com o tempo de roundtrip obtido de informações dos pacotes de dados proveniente da planta. Para se chegar a tal solução, foi analisada nas primeiras seções a influência do atraso em malhas de controle e posteriormente um estudo do estado da arte para tipos de controle sobre redes IP. Ao final é apresentada uma análise experimental, demonstrando resultados promissores da aplicação desta proposta. / This work presents a solution to compensate the varying delay, characteristic of IP networks. The Smith predictor is traditionally used to compensate delays but in this type of networks an other important factor that can destabilize the system is the large jitter of the delay. In order to solve this problem, the solution presented here is based on a data structure to save the output from the model of the plant used by the Smith predictor, that make possible to compare the output from the plant with the corresponding value in the structure. In order to take the correspondent value, it is associated to an index which is calculated with the roundtrip obtained from the informations in the packet arrived from the plant. In order to formulate this solution, it was analised in the first sections the influence of the delay in control systems and then a study of the state of art of the control systems over IP networks. At the end, an experimental analise to demonstrate the good result of the application of this solution is presented.

Orientador: Lee Luan Ling / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-10T06:59:04Z (GMT). No. of bitstreams: 1 Perlingeiro_FirmianoRamos_D.pdf: 3410071 bytes, checksum: c0484605d794231363118e1130a5e764 (MD5) Previous issue date: 2006 / Resumo: O provisionamento de QoS garantida é de extrema importância no desenvolvimento das futuras redes. Os recentes avanços tecnológicos em comutação e em transmissão permitem a implementação de redes com velocidades extremamente altas que podem transportar grandes quantidades de tráfego geradas por aplicações mais sensíveis aos requisitos de qualidade de serviço. A próxima geração de redes deverá suportar novas aplicações multimídia em um ambiente global e disponibilizar novos serviços em plataformas flexíveis sem necessidade de alteração da infra-estrutura. Isto requer uma nova arquitetura de redes capaz de oferecer serviços de transporte e de processamento para aplicações de comunicação com fortes requisitos de QoS. No amplo escopo da engenharia de tráfego de redes e do provimento de serviços com qualidade assegurada, esta tese se dedica a propor algumas soluções para os problemas de alocação de recursos de rede, em especial soluções para a estimação da banda efetiva. Para tanto, se utiliza de forma intensiva a caracterização de tráfego, métodos analíticos, heurísticos e de simulação. Os métodos propostos de alocação de banda neste estudo estão fundamentados na Teoria dos Grandes Desvios, aproximação Gaussiana e de caracterização de tráfego. Em termos de caracterização de tráfego, além de vários parâmetros já adotados na literatura é abordada a teoria fractal, incluindo mono e multifractais em seus diferentes aspectos, e ainda, é introduzido um novo parâmetro de tráfego que inclui as características mono e multifractal. Adicionalmente são consideradas as restrições de atraso e jitter, através de adoção de critérios para validação da estimação da banda efetiva, para tráfego em tempo real. A validação da metodologia proposta neste trabalho foi efetivada através de exaustivos testes de simulação com arquivos de tráfego real / Abstract: The assured QoS provisioning has great importance in the development of future networks. Recently, the technological advances in transmission and switching has allowed the implementation of very high speed networks which can transport a huge amount of traffic generated by QoS sensitive applications. The next generation networks must support new multimedia applications in a global environment and deliver new services over flexible platforms without the need of change in the infrastructure. That means that the new network architecture has to be able to transport and process information with strong QoS requirements. Under the wide scope of teletraffic engineering and assured quality of service provisioning, this thesis proposes solutions for some open problems of network resource allocation, especially bandwidth allocation. In order to get reliable solutions, we use intensive traffic characterization, analytical and heuristical methods and simulations. The proposed bandwidth allocation methods in this study are based on the Large Deviation Theory, Gaussian Approximation and traffic characterization. In terms of traffic characterization, in addition to the well known traffic parameters, the fractal theory, including mono and multifractals, are considered. Besides, we introduce a new traffic parameter that takes the mono and multifractal characteristics into account. The proposed bandwidth estimation approaches were tested with real real time traffic under both delay and jitter criteria. All proposed methodologies in this work have been validated by exhaustive simulation tests with real traffic traces / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica

Este trabalho apresenta uma proposta de solução para compensar o atraso variável, característico de redes IP. O preditor de Smith é tradicionalmente usado para compensar atrasos, mas no caso deste tipo de rede um fator importante que pode degradar o controle do sistema são as grandes variações nos atrasos sofridos pelas mensagens. Para tratar este problema, este trabalho baseia-se na criação de uma estrutura de dados de armazenamento para a saída do preditor de Smith, possibilitando a comparação do valor de saída da planta com o valor adequado guardado na estrutura. Para determinação do valor correspondente, este está associado a um índice calculado com o tempo de roundtrip obtido de informações dos pacotes de dados proveniente da planta. Para se chegar a tal solução, foi analisada nas primeiras seções a influência do atraso em malhas de controle e posteriormente um estudo do estado da arte para tipos de controle sobre redes IP. Ao final é apresentada uma análise experimental, demonstrando resultados promissores da aplicação desta proposta. / This work presents a solution to compensate the varying delay, characteristic of IP networks. The Smith predictor is traditionally used to compensate delays but in this type of networks an other important factor that can destabilize the system is the large jitter of the delay. In order to solve this problem, the solution presented here is based on a data structure to save the output from the model of the plant used by the Smith predictor, that make possible to compare the output from the plant with the corresponding value in the structure. In order to take the correspondent value, it is associated to an index which is calculated with the roundtrip obtained from the informations in the packet arrived from the plant. In order to formulate this solution, it was analised in the first sections the influence of the delay in control systems and then a study of the state of art of the control systems over IP networks. At the end, an experimental analise to demonstrate the good result of the application of this solution is presented.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-03-02T13:44:12Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissert_Alexandre_Santos_CIN.pdf: 2195136 bytes, checksum: bc5b11111393e727688fe5580cf6f0b4 (MD5) / Made available in DSpace on 2017-03-02T13:44:12Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissert_Alexandre_Santos_CIN.pdf: 2195136 bytes, checksum: bc5b11111393e727688fe5580cf6f0b4 (MD5) Previous issue date: 2016-07-28 / Com o crescimento da adoção de comunicação de voz em redes de dados, tecnologia conhecida como Voice Over Internet Protocol (VoIP) , tornaram-se evidentes, tanto vantagens obtidas, quanto problemáticas decorrentes do contraste entre a natureza das redes de dados e as necessidades do tráfego VoIP. A internet não possui, por padrão, formas inteligentes de proteção e priorização do tráfego, levando à utilização de tecnologias externas para suprir estas necessidades. Todavia, a utilização destas tecnologias tem tornado-se cada vez mais complexa em virtude de um fenômeno conhecido como ossificação das redes IP, conforme Mckeown et al. (2008). Em busca de solucionar os problemas enfrentados pelas redes atuais e prover maior flexibilidade e capacidades inovadores, surge a Software Defined Network (SDN), tecnologia que visa trazer uma série de vantagens para as redes de dados atuais através de sua arquitetura. Neste trabalho é proposta a VoIPath, uma solução baseada em SDN que implementa uma técnica de seleção de caminhos com base em atributos específicos, relevantes para o tráfego VoIP. Para processar estes atributos e identificar os melhores caminhos para o tráfego VoIP é empregado um algoritmo criado com programação linear, onde um volume de tráfego VoIP é dividido entre diferentes caminhos, com base em opções de execução da solução. Para controlar a propagação do tráfego é empregada uma tecnologia baseada em SDN a Virtual Tenant Networks (VTN), através desta o tráfego é conduzido por uma rede lógica, chamada de tenant. O mapeamento destas redes lógicas na rede SDN física garante a passagem do tráfego pelos caminhos selecionados. Por fim é realizada uma série de experimentos para demonstrar a efetividade da solução, bem como melhorias na qualidade do áudio, calculadas com base em um modelo de avaliação de qualidade de tráfego VoIP. / With increasing adoption of voice communications through data networks, technology known as VoIP, both advantages and issues have become apparent. The second group caused by the contrast between the nature of data networks and the needs of VoIP traffic. By default, data networks do not have smart structures to protect and prioritize traffic. In order to achieve these characteristics external technologies are deployed, but the utilization of such strategy has become complex due to a phenomenon described as network ossification (MCKEOWN et al., 2008). In order to provide solutions to the problems of the actual data networks architecture and provide greater flexibility, comes in scene the SDN technology. The SDN architecture unleashes a new horizon of possibilities to the networks. This work proposes the VoIPath solution, which consists of a implementation of a SDN based path selection technique, oriented by specific relevant attributes to the VoIP traffic. A algorithm created with linear programming is employed to compute these attributes and identify the best paths to the VoIP traffic, which is divided through the network, in according to execution parameters. In order to control the traffic propagation is employed the VTN technology, which consists on an SDN based solution. Through VTN technology the VoIP traffic is forwarded through an logical network called tenant. The mapping of the tenant over the physical network ensures that the selected paths are employed. To ensure the solution’s effectiveness a series of experiments are performed and the impact of its’s execution on the audio is calculated with the usage of an VoIP quality measurement evaluation model.

The goal of the thesis is to develop and describe application for Mikrotik Network stress testing. The aplication is developed in high-level scripting programming language Python. The aplication allowed us to configure and display in diagram our connected routers and network stress testing. Theoretical part is focused on Mikrotik company, their development and products. Next part is about theory of network stress testing and graph theory. The last part is about aplications development, programming language Python and used tools and libraries.

When it comes to their Radio Access Network (RAN) infrastructure, no two Mobile Operators, serving remote service areas, are alike. Despite situations and technologies being diverse, a well designed optimized RAN solution must adapt itself to the existing networking technologies, both with regard to legacy core networks and modern telecommunication networks in order to produce the best network which is possible subject to many constraints. There is a misconception in technical circles that an optimized internet protocol (IP) enabled RAN architecture is more theoretical than practical. On the contrary, the aforesaid is highly dependent on the technology used. Packet optimized IP- GSM Radio Access Network (GRAN) architecture is proposed in this thesis, it uses Internet Protocol (IP) rather than proprietary protocols for communication between Base Transceiver Stations (BTS), Base Station Controllers (BSC), and the Network Switching Subsystem (NSS). This architecture must deliver carrier-grade mobility, scalability, and reliability; while being optimized for efficient roaming, routing and backhauling from remote service areas. In a geographic arena that spans across the globe, classical circuit-switched networks are not cost efficient due to their integrated call control (signaling) and switching architecture. A solution to this may be soft-switching which separates the call control (Media Gateway Controller (MGC)) and switching (Media Gateway (MG)) into separate nodes. This methodology would fundamentally change the way circuit-switched services, such as traditional voice telephony, are handled. For a service provider this enables a much more efficient network, because it allows optimized equipment location for voice termination into other carrier networks. Co-location of media gateways with satellite ground stations enables local termination to the public switched telephone network (PSTN), thus offloading a great deal of the traffic from the backhaul transmission network of the mobile operator. This thesis adopts soft-switching as part of the call routing processes. The thesis considers the problem of transporting voice and signaling from-to the remote service areas, efficient routing and backhaul to the location of most suitable operator’s point of presence. The thesis explores an alternative which uses a packet switched backbone (e.g. IP based) to transport the media as close (geographically) to the dialed party as possible before terminating it at the PSTN network, thus achieving optimal routing of voice and signaling. Considering the aforesaid, the thesis describes a detailed network architecture and an operational system prototype for maritime GSM network deployment, as a befitting and challenging example of remote service area. / När det gäller deras Radio access nät, finns det inte två Mobiloperatörer, som betjänar avlägsna områden, som är lika. Trots olika omständigheter och teknologier, ett väl designat optimerat RAN måste anpassa sig till den existerande nätverks teknologin, både med avseende på äldre befintlig teknologi och på moderna telekomnät, för att kunna skapa bästa möjliga nätverk givet många begränsningar. Det är en missuppfattning i tekniska kretsar att en optimerad IP anpassad RAN arkitektur är mer teoretisk än praktisk. Å andra sidan så är det ovan sagda väldigt beroende på vilken teknologi som har använts. En paket optimerad IP-GSM Radio Access Nätverks (IPGRAN) arkitektur är föreslagen i denna masters uppsats, den baseras på Internet Protokollet (IP) snarare än något egenutvecklat proprietärt protokol för komunikation mellan Basstation (BTS), Basstationscontroller (BSC), och nätets switchade subsystem (NSS). Denna arkitektur måste leverera carrier-grade (operatörs klassad) mobilitet, skalbarhet och tillgänglighet och samtidigt vara optimerat för effektiv roaming, routing och anslutning från avlägsna områden. På ett geografiskt område som sträcker sig runt hela jordklotet är inte klassiska kretskopplade nätverk kostnadseffektiva beroende på deras integrerade signallerings och samtals arkitektur. En bättre arkitektur kan vara en sk “softswitch” lösning som separerar samtalet i en (Media Gateway Controller (MGC)) och signaleringen (Media Gateway (MG)) i separata noder. Denna metod skulle på ett fundamentalt vis ändra det sätt på vilket traditionella kretskopplade tjänster som traditionell telefoni hanteras. För en tjänsteleverantör möjliggör detta ett mycket effektivare nätverk då det möjliggör optimerad utplacering av utrustning för terminering av rösttrafik in i andra operatörers nät. Samlokalisering av media gateways (MG:s) med jordstationer för satellitkommunikation möjliggör lokal anslutning till det allmänna telenätet (PSTN), vilket kraftigt minskar den trafik som behöver transporteras genom operatörens stomnät. Denna mastersuppsats behandlar “softswitching” som en del av metoden att växla och transportera samtalstrafik. Uppsatsen behandlar problemet med att skicka samtalstrafik och signalering från avlägsna områden, effektiv routing och transport av trafiken till den operatör som har den närmaste(alt. mest optimala) anslutningspunkten. Uppsatsen undersöker ett alternativ som använder ett paketförmedlat (IP baserat) transportsätt för att transportera trafiken geografiskt sett så nära den uppringda parten som möjligt innan den termineras i det allmänna telenätet (PSTN) varvid man uppnår optimal växling (alt. routing) av rösttrafik och signalering. I beaktande av ovanstående beskriver uppsatsen en detaljerad nätverksarkitektur och en funktionsduglig systemprototyp för ett maritimt GSM nät som ett utmanande exempel på ett avlägset beläget nät.

Critical networks require defence in depth incorporating many different security technologies including intrusion detection. One important intrusion detection approach is called anomaly detection where normal (good) behaviour of users of the protected system is modelled, often using machine learning or data mining techniques. During detection new data is matched against the normality model, and deviations are marked as anomalies. Since no knowledge of attacks is needed to train the normality model, anomaly detection may detect previously unknown attacks. In this thesis we present ADWICE (Anomaly Detection With fast Incremental Clustering) and evaluate it in IP networks. ADWICE has the following properties: (i) Adaptation - Rather than making use of extensive periodic retraining sessions on stored off-line data to handle changes, ADWICE is fully incremental making very flexible on-line training of the model possible without destroying what is already learnt. When subsets of the model are not useful anymore, those clusters can be forgotten. (ii) Performance - ADWICE is linear in the number of input data thereby heavily reducing training time compared to alternative clustering algorithms. Training time as well as detection time is further reduced by the use of an integrated search-index. (iii) Scalability - Rather than keeping all data in memory, only compact cluster summaries are used. The linear time complexity also improves scalability of training. We have implemented ADWICE and integrated the algorithm in a software agent. The agent is a part of the Safeguard agent architecture, developed to perform network monitoring, intrusion detection and correlation as well as recovery. We have also applied ADWICE to publicly available network data to compare our approach to related works with similar approaches. The evaluation resulted in a high detection rate at reasonable false positives rate. / <p>Report code: LiU-Tek-Lic-2006:12.</p>