TCP Versus UDP Performance in Term of Bandwidth Usage

This project is mainly about how to establish User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) connection in the same network simulation. For that, we will be using four types of TCP which are TCP Tahoe, TCP Reno, TCP NewReno and TCP Vegas. From there, we are going to differentiate them in term bandwidth usage and define how it works and describes several effect that occurred when its work together. In order to create the topology and run the protocols, we use Network Simulator 2 (NS2) to create and run the coding. To run the codes, we use command which use a few code in running the coding. Then we will get a topology,which is the flow of the packet within the source and destination, base on the coding. A graph also appears after the command

Алгоритмы конвейерного интервального анализа трафика

The problem of real-time queue analysis of production IP traffic is stated. The method of interval analysis is described in context of real-time constraints. Drawbacks of such method are stated and solutions proposed. First, we propose an algorithm to enhance interval analysis support for variable length analysis which is crucial for real IP-TV traffic. We consider different units to measure packet to customer in the queue mapping. We estimate the 1KB worth of packet data to be a viable fit to calculate accurate queue sizes. Then we propose pipeline extension for interval analisys as a sliding window. We introduce sliding window on timestamp scale and describe evolution models of left and right window edge separately. The algorithm proposed to map timestamps to number of customer in the queue. All proposed techniques then combined into algorithm of reverse queue calculation with parallel calculation of several service intervals simultaneously. We demonstrate and measure a performance of reference implementation of said algorithms in the lab under H.264 IP-TV traffic of various rates.Рассматривается модель участка доступа мультисервисной сети оператора связи от магистральной линии до порта абонента. Рассматривается трафик мультисервисной сети на данном участке. Сформулированы проблемы, возникающие при анализе свойств очередей IP-TV видеотрафика стандарта H.264 в реальном времени. Приводится описание интервального метода анализа трафика и предлагается ряд алгоритмов, расширяющих и дополняющих этот метод. Интервальный метод дополняется возможностью анализа реальных потоков трафика заявок произвольной длины. Рассматривается вопрос выбора единицы квантизации длины заявки. За единицу времени обработки заявки в интервальном методе принимается время обработки исходящим каналом 1 КБ данных. Подтверждена справедливость формул интервального метода для расчета дифференциальной интенсивности событий и дифференциального коэффициента загрузки. Рассматривается работа интервального метода с поддержкой пакетов произвольной длины в режиме конвейера реального времени с непрерывно поступающими заявками. Предлагается алгоритм конвейеризации в виде «скользящего окна». Вводится понятие скользящего окна на пространстве временных меток заявок. Рассматривается возможность независимой эволюции границ окна. Алгоритм предусматривает расчет количества заявок на интервалах обслуживания и определение размеров очередей при заданных коэффициентах загрузки. Предложен способ получения указанных величин в аналогичном скользящем окне в зависимости от интервалов обслуживания. В результате приводится алгоритм обратного асинхронного расчета очереди для параллельной обработки скользящего окна с разными значениями коэффициента загрузки. Демонстрируются результаты реализации данных алгоритмов в рамках с работы системы конвейерного интервального анализа трафика на тестовом стенде

Statistical methods used for intrusion detection

Thesis (Master)--Izmir Institute of Technology, Computer Engineering, Izmir, 2006Includes bibliographical references (leaves: 58-64)Text in English; Abstract: Turkish and Englishx, 71 leavesComputer networks are being attacked everyday. Intrusion detection systems are used to detect and reduce effects of these attacks. Signature based intrusion detection systems can only identify known attacks and are ineffective against novel and unknown attacks. Intrusion detection using anomaly detection aims to detect unknown attacks and there exist algorithms developed for this goal. In this study, performance of five anomaly detection algorithms and a signature based intrusion detection system is demonstrated on synthetic and real data sets. A portion of attacks are detected using Snort and SPADE algorithms. PHAD and other algorithms could not detect considerable portion of the attacks in tests due to lack of sufficiently long enough training data

Unified congestion control for unreliable transport protocols

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 55-58).by Hariharan Shankar Rahul.S.M

An investigation into the design and implementation of an internet-scale network simulator

Simulation is a complex task with many research applications - chiey as a research tool, to test and evaluate hypothetical scenarios. Though many simulations execute similar operations and utilise similar data, there are few simulation frameworks or toolkits that allow researchers to rapidly develop their concepts. Those that are available to researchers are limited in scope, or use old technology that is no longer useful to modern researchers. As a result of this, many researchers build their own simulations without a framework, wasting time and resources on a system that could already cater for the majority of their simulation's requirements. In this work, a system is proposed for the creation of a scalable, dynamic-resolution network simulation framework that provides scalable scope for researchers, using modern technologies and languages. This framework should allow researchers to rapidly develop a broad range of semantically-rich simulations, without the necessity of superor grid-computers or clusters. Design and implementation are discussed and alternative network simulations are compared to the proposed framework. A series of simulations, focusing on malware, is run on an implementation of this framework, and the results are compared to expectations for the outcomes of those simulations. In conclusion, a critical review of the simulator is made, considering any extensions or shortcomings that need to be addressed

Internet Traffic and Topology Characteristics from a National ISP Perspective

Measurement is the first step in predicting the growth of Internet. They can reveal information about traffic and topology characteristics of the Internet. Understanding traffic and topology characteristics are vital for evaluating the performance of networking protocols, creating accurate models for simulation and helping service providers to better utilize their resources. Using the data collected from a National Internet Service Provider in Kosovo, PTK, we report on traffic measurements and analyze some of the most important characteristics of Internet traffic such as self-similarity and long-range dependence. Also, we reveal information about the topology structure of Internet at IP level, from the perspective of our data

Desenvolvimento de um Bandwidth Broker para a arquitetura de serviços diferenciados

Orientador: Edmundo Roberto Mauro MadeiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: o controle da qualidade de serviço em diferentes níveis de granularidade permite idealizar uma série de novas aplicações com exigências críticas de desempenho. Este trabalho explora este novo cenário, apresentando a base desta discussão e propondo um modelo de desenvolvimento. Um protótipo foi implementado para validar estas novas estratégias de controle da qualidade de serviço. A evolução das estratégias de diferenciação de serviços é apresentada, como referência da discussão da oferta de controle da qualidade de serviço através de políticas de alto­nível. Este trabalho se concentra na proposta de um modelo de camadas de atuação, discutindo as funcionalidades de cada camada e a interação necessária para oferecer o gerenciamento de recursos. O conceito de Bandwidth Broker foi apresentado como solução do problema de gerência em diferentes níveis de atuação. Apresentou-se uma modelagem deste tipo de gerente, através da proposta de um modelo de desenvolvimento e da identificação das funcionali­dades dos componentes do modelo. Diversos casos de uso discutem estas funcionalidades, identificando os participantes no processo de gerência, desde os níveis mais altos de ad­ministração até o nível de elemento de rede. A implementação do protótipo foi realizada inserindo modificações no simulador de redes NS, que permitiram um agente externo distribuir informações de configuração e atuar no ajuste dos mecanismos de encaminhamento. Os experimentos simularam tráfegos com diferentes requisitos de qualidade de serviço, através de cenários que mostram o impacto positivo do controle em diferentes níveis de atuação, através da intervenção do Bandwidth Broker. Através da definição de políticas simples, demonstrou-se uma estratégia na qual o Bandwidth Broker atua para estabilizar requisições de recursos que competem entre si. Ainda, o impacto que diferentes tipos de tráfego da rede inserem na utilização de recursos de rede foi discutido, assim como o Bandwidth Broker pode resolver este problemaResumo: The quality of service control on different granularity levels allows to perform of a set of new applications with performance demands. This work explores this new scenario, presenting the basis of this discussion and proposing a development model. A prototype has been implemented, to validate these new quality of service control strategies. The evolution of service differentiation strategies is presented, as a reference for the discussion of quality of service control through high leveI policies. This work concentrates on the proposal of a provisioning tier model, discussing each leveI functionalities and their interactions to offer the resource management capability. The Bandwidth Broker concept was presented as a solution to the management pro­blem at different levels of provisioning. A model of this kind of manager was presented, through the proposal of a development modeI and the identification of the funcionalities of the model's components. Several use cases discuss these funci(~nalities, identifing the players on the management process, from highest levels of administration down to the network elemento. The prototype implementation was done through modifications of the network simu­lator (NS), which allowed an external agent to distribute configuration information and to perform forwarding mechanism adjustments. The experiments simulated traffic with different QoS requirements, through scenarios that showed the positive impact of controI at different levels of provisioning, through the Bandwidth Broker intervation.Through the definition of simple policies, it was demonstrated a strategy that the Bandwidth Broker acts to stabilize competing resource requirements. Furthermore, we discussed the impact that different types of network traffic cause on the utilization of network resources and how the Bandwidth Broker can solve this probIemMestradoMestre em Ciência da Computaçã

Fractal-based models for internet traffic and their application to secure data transmission

This thesis studies the application of fractal geometry to the application of covert communications systems. This involves the process of hiding information in background noise; the information being encrypted or otherwise. Models and methods are considered with regard to two communications systems: (i) wireless communications; (ii) internet communications. In practice, of course, communication through the Internet cannot be disassociated from wireless communications as Internet traffic is 'piped' through a network that can include wireless communications (e.g. satellite telecommunications). However, in terms of developing models and methods for covert communications in general, points (i) and (ii) above require different approaches and access to different technologies. With regard to (i) above, we develop two methods based on fractal modulation and multi-fractal modulation. With regard to (ii), we implement a practical method and associated software for covert transmission of file attachments based on an analysis of Internet traffic noise. In both cases, however, two fractal models are considered; the first is the standard Random Scaling Fractal model and the second is a generalisation of this model that incorporates a greater range of spectral properties than the first—a Generalised Random Scaling Fractal Model. [Continues.

Uma política de escalonamento para servidores web baseada na velocidade da conexão

Orientadora: Cristina Duarte MurtaDissertação (mestrado) - Universidade Federal do ParanáResumo: Esta dissertação propõe uma nova política de escalonamento para o processamento de requisições HTTP estáticas em servidores Web. Esta nova política chama-se FCF (Fastest Connection First). A política proposta atribui prioridades às requisições HTTP baseando-se no tamanho do arquivo solicitado e na velocidade da conexão com o usuário. As requisições para arquivos menores feitas através de conexões mais rápidas recebem maior prioridade. O que motivou a proposição desta política de escalonamento foi a distribuição dos tamanhos de arquivo transferidos na Web, a diversidade de condições de conectividade observadas na Internet e a possibilidade de saber com antecedência o tamanho do processo para atender a requisições estáticas. O objetivo da política FCF é otimizar a interação entre servidor Web e Internet visando um menor tempo final de resposta. A nova política foi comparada através de simulação com as políticas de uso corrente em servidores Web e também com a política SRPT (Shortest Remaining Processing Time). Os resultados apresentam evidências de que as diferenças de conectividade observadas na Internet afetam o desempenho do servidor, e que essa informação pode ser utilizada para melhorar significativamente o desempenho do sistema. Além disso, comprovou-se que a distribuição dos tamanhos de arquivo da Web evita que ocorra starvation de processos grandes quando aplica-se políticas de escalonamento que priorizem processos pequenos.Abstract: This dissertation proposes a new scheduling policy for the processing of static HTTP requisitions in Web servers. This policy, called FCF (Fastest Connection First), gives priority to HTTP requests based on fie size of the requested file and on the speed of the user's connection. The requests for smaller files through fester connections receive the highest priorities. The motivation of this proposal is the distribution of the file sizes transferred in the Web, the diversity of the effective bandwidth of the user's connection observed in the Internet and the possibility of knowing the size of the process in advance. The new policy was compared through simulation with the policies standard in Web servers and also with the policy SRPT (Shortest Remaining Processing Time). The results show evidences that the different levels of connectivity in the Internet affect the performance of the Web server, and that this information can be used to improve the performance of the system significantly. We showed that the distribution of the Web files sizes avoids starvation of big processes if a size based scheduling policy is applied

Novel localised quality of service routing algorithms. Performance evaluation of some new localised quality of service routing algorithms based on bandwidth and delay as the metrics for candidate path selection.

The growing demand on the variety of internet applications requires management of large scale networks by efficient Quality of Service (QoS) routing, which considerably contributes to the QoS architecture. The biggest contemporary drawback in the maintenance and distribution of the global state is the increase in communication overheads. Unbalancing in the network, due to the frequent use of the links assigned to the shortest path retaining most of the network loads is regarded as a major problem for best effort service. Localised QoS routing, where the source nodes use statistics collected locally, is already described in contemporary sources as more advantageous. Scalability, however, is still one of the main concerns of existing localised QoS routing algorithms. The main aim of this thesis is to present and validate new localised algorithms in order to develop the scalability of QoS routing. Existing localised routing, Credit Based Routing (CBR) and Proportional Sticky Routing (PSR), use the blocking probability as a factor in selecting the routing paths and work with either credit or flow proportion respectively, which makes impossible having up-to-date information. Therefore our proposed Highest Minimum Bandwidth (HMB) and Highest Average Bottleneck Bandwidth History (HABBH) algorithms utilise bandwidth as the direct QoS criterion to select routing paths. We introduce an Integrated Delay Based Routing and Admission Control mechanism. Using this technique Minimum Total Delay (MTD), Low Fraction Failure (LFF) and Low Path Failure (LPF) were compared against the global QoS routing scheme, Dijkstra, and localised High Path Credit (HPC) scheme and showed superior performance. The simulation with the non-uniformly distributed traffic reduced blocking probability of the proposed algorithms. Therefore, we advocate the algorithms presented in the thesis, as a scalable approach to control large networks. We strongly suggest that bandwidth and mean delay are feasible QoS constraints to select optimal paths by locally collected information. We have demonstrated that a few good candidate paths can be selected to balance the load in the network and minimise communication overhead by applying the disjoint paths method, recalculation of candidate paths set and dynamic paths selection method. Thus, localised QoS routing can be used as a load balancing tool in order to improve the network resource utilization. A delay and bandwidth combination is one of the future prospects of our work, and the positive results presented in the thesis suggest that further development of a distributed approach in candidate paths selection may enhance the proposed localised algorithms.Umm AlQura University in Mecc