Multimedia performance evaluation of ethernet and token ring media access protocols: a network comparison

This paper and accompanying project examines which type of time-division multiplexing media access protocol, the Carrier Sense Multiple Access (CSMA) of Ethernet or the token passing of token ring, is best able to fulfill the stringent isochronous performance demands required of today's resource-hungry multimedia networks, specifically the requirements of high throughput, low latency and jitter, and minimal error rates. Using performance bounds accepted by other researchers as sufficient to ensure quality isochronous transmission, that of (1) the throughput rate being equal to or less than the playback rate; (2) the latency in transmitting each packet ranging from 20 to 400 milliseconds and the variance or jitter being less than 80 milliseconds; and (3) the rate of lost packets ranging from 0.01--1.001, this paper approaches a solution first from the theoretical and then integrates into the final conclusion an analytical, C++ software evaluation test component that models network performance under optimum conditions. The immediate benefit of the entire study is the identification of one media access protocol, Ethernet or Token Ring, over its counterpart as being superior for isochronous applications as defined by the above performance requirements, and the long-term consequence of this identification will be facilitating for future network designers, including those of digital libraries, the selection of the best network architecture for their multimedia environments

Scheduling of Real-time Traffic in a Switched Ethernet Network

Traditional Ethernet networks are not suitable for real-time communication due to the nondeterministic handling of the network communication. The reason for the nondeterministic behavior is the CSMA/CD access control protocol that is used when the media is shared. The protocol can cause collision in the transmission. If this happens the transmission ceases and after a random amount of time a retransmission is tried. Over the years Ethernet transmission rate and communication reliability have increased, which make it a more interesting alternative for periodic real-time communication with a high update rate. This master thesis investigates if it is possible to avoid the nondeterministic behavior of Ethernet, by scheduling the periodic real-time traffic in a switched network

Future of asynchronous transfer mode networking

The growth of Asynchronous Transfer Mode (ATM) was considered to be the ideal carrier of the high bandwidth applications like video on demand and multimedia e-learning. ATM emerged commercially in the beginning of the 1990\u27s. It was designed to provide a different quality of service at a speed up 100 Gbps for both real time and non real time application. The turn of the 90\u27s saw a variety of technologies being developed. This project analyzes these technologies, compares them to the Asynchronous Transfer Mode and assesses the future of ATM

Análise de desempenho de um cluster para execução do modelo de previsão do tempo ARPS

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação.Este trabalho consiste em um estudo de diferentes alternativas d

Ethernet Networks for Real-Time Use in the ATLAS Experiment

Ethernet became today's de-facto standard technology for local area networks. Defined by the IEEE 802.3 and 802.1 working groups, the Ethernet standards cover technologies deployed at the first two layers of the OSI protocol stack. The architecture of modern Ethernet networks is based on switches. The switches are devices usually built using a store-and-forward concept. At the highest level, they can be seen as a collection of queues and mathematically modelled by means of queuing theory. However, the traffic profiles on modern Ethernet networks are rather different from those assumed in classical queuing theory. The standard recommendations for evaluating the performance of network devices define the values that should be measured but do not specify a way of reconciling these values with the internal architecture of the switches. The introduction of the 10 Gigabit Ethernet standard provided a direct gateway from the LAN to the WAN by the means of the WAN PHY. Certain aspects related to the actual use of WAN PHY technology were vaguely defined by the standard. The ATLAS experiment at CERN is scheduled to start operation at CERN in 2007. The communication infrastructure of the Trigger and Data Acquisition System will be built using Ethernet networks. The real-time operational needs impose a requirement for predictable performance on the network part. In view of the diversity of the architectures of Ethernet devices, testing and modelling is required in order to make sure the full system will operate predictably. This thesis focuses on the testing part of the problem and addresses issues in determining the performance for both LAN and WAN connections. The problem of reconciling results from measurements to architectural details of the switches will also be tackled. We developed a scalable traffic generator system based on commercial-off-the-shelf Gigabit Ethernet network interface cards. The generator was able to transmit traffic at the nominal Gigabit Ethernet line rate for all frame sizes specified in the Ethernet standard. The calculation of latency was performed with accuracy in the range of +/- 200 ns. We indicate how certain features of switch architectures may be identified through accurate throughput and latency values measured for specific traffic distributions. At this stage, we present a detailed analysis of Ethernet broadcast support in modern switches. We use a similar hands-on approach to address the problem of extending Ethernet networks over long distances. Based on the 1 Gbit/s traffic generator used in the LAN, we develop a methodology to characterise point-to-point connections over long distance networks. At higher speeds, a combination of commercial traffic generators and high-end servers is employed to determine the performance of the connection. We demonstrate that the new 10 Gigabit Ethernet technology can interoperate with the installed base of SONET/SDH equipment through a series of experiments on point-to-point circuits deployed over long-distance network infrastructure in a multi-operator domain. In this process, we provide a holistic view of the end-to-end performance of 10 Gigabit Ethernet WAN PHY connections through a sequence of measurements starting at the physical transmission layer and continuing up to the transport layer of the OSI protocol stack

Implementation, verification and synthesis of the Gigabit Ethernet 1000BASE-T Physical Coding Sublayer

To meet the increasing demand for additional bandwidth requirements, high-speed connections are required to reduce traffic bottlenecks and improve performance on network systems. Gigabit Ethernet offers a cost-effective solution that is compatible with existing technologies to protect large investments in network infrastructure. IEEE standard 802.3ab 1000BASE-T (Gigabit Ethernet) physical layer standard offers this solution which upgrades networks to 1000Mbps data rates while maintaining the simplicity and manageability of the existing Ethernet networks, just as 100BASE-T Ethernet extended 10BASE-T Ethernet networks. The 1000BASE-T physical layer standard providing 1Gbps Ethernet signal transmission over four pairs of category 5 unshielded twisted pair (UTP) cable using the 5-level coding scheme. The Physical Coding Sublayer (PCS) of IEEE 802.3ab 1000BASE-T physical layer was developed and implemented. The behavioral modeling, functional modeling and simulation were done using Verilog HDL[Registered trademark symbol). Then, the PCS was synthesized using two process libraries: 0.35[Mu]m CMOS and 1.4[Mu]m CMOS. Two synthesis techniques, hierarchical optimization and hierarchical-flattening optimization, were explored to compare the area and timing tradeoffs between them. The automation of the synthesis was accomplished with the creation of synthesis script files. With these script files, the PCS can be synthesized automatically with any target library desired

Robustness of Ethernet-Based Real-Time Networked Control System with Multi-Level Client/Server Architecture

The importance of real-time communication at the device level in a factory automation setup is a widely researched area. This research is an effort to experimentally verify if Ethernet can be used as a real-time communication standard in a factory automation setup, by observing the effects of packet delays, packet loss, and network congestion on the performance of a networked control system (NCS). The NCS experimental setup used in this research involves real-time feedback control of multiple plants like DC motors and a magnetic-levitation system connected to one or more controllers. A multi-client-multi-server architecture on a local area network (LAN) was developed using user datagram protocol (UDP) as the communication protocol. Key observations are as follows. (1) The multi-client-single-server system showed the highest packet delays compared to single-client-single-server architecture. (2) In the singleclient- single-server system, as the Ethernet link utilization increased beyond 82 percent, the average packet delays and steady-state error of the DC motor speed-control system increased by 2231 percent and 304 percent, respectively. (3) Even under high link utilization, adding an additional server to the NCS reduced average packet delays considerably. (4) With large packet sizes, higher packet rates were automatically throttled by Ethernet’s flow control mechanism affecting the real-time communication negatively. (5) In the multiclient- multi-server architecture, average packet delays at higher packet rates, and at higher packet lengths were found to be 40 percent lesser than the those of the single-clientsingle- server system and 87.5 percent lesser than those of the multi-client-single-server system

Development of computer network project for companies office

Кваліфікаційна робота присвячена розробці проекту комп'ютерної мережі для офісу компанії. Метою роботи є розробка проекту комп’ютерної мережі з урахуванням архітектурних особливостей офісної будівлі компанії, а також особливостей функціонування компанії. У першому розділі кваліфікаційної роботи розглянуто особливості моделі OSI, за якою проектуються сучасні комп’ютерні мережі. У другому розділі кваліфікаційної роботи наведено обґрунтування вибору та розрахунку технології Fast «Ethernet» як основи для проектованої комп’ютерної мережі. У третьому розділі кваліфікаційної роботи представлено процес проектування мережі та отримані результати, зокрема: побудова технічної моделі, підготовка мережевої документації, план підключення обладнання, розрахунок пропускної здатності мережі, кошторисна вартість проекту. Qualification work is devoted to the development of a computer network project for companies office. The purpose of the work is to develop a computer network project taking into account the architectural features of the company's office building as well as the peculiarities of the company's operation. In the first section of the qualification work the features of the OSI model are considered, according to which modern computer networks are designed. The second section of the qualification work provides a rationale for the choice and calculation of Fast «Ethernet» technology as a basis for the designed computer network. The third section of the qualification work presents the process of network design and the results obtained, in particular: construction of a technical model, network documentation preparation, plan for connecting equipment, calculation of network bandwidth, estimated cost of the project.INTRODUCTION 8 1 THE OSI REFERENCE NETWORK MODEL IN OVERVIEW 10 1.1 The “OSI” model 10 1.2 Stages of OSI model 11 1.3 Conclusion of the chapter 1 15 2 FAST «ETHERNET» NETWORK CALCULATION 17 2.1 «Ethernet» technology 17 2.2 Fast «Ethernet» technology 19 2.3 Rules for building a Fast «Ethernet» network 21 2.3.1 Calculation of the first model 21 2.3.2 Calculation of second model 25 2.3.3 Example of Fast «Ethernet» network configuration calculation 27 2.4 Conclusion of the chapter 2 28 3 STAGES OF STRUCTURED CABLING DESIGN 31 3.1 Terms of reference of the customer 31 3.2 Construction of a technical model 33 3.3 Preparation network documentation 39 3.4 Connecting equipment plan 41 3.5 Calculation of network bandwidth that is useful 49 3.6 Modeling of networks 51 3.7 Estimated cost of the project 52 3.8 Conclusion of the chapter 3 53 4 OCCUPATIONAL HEALTH AND EMERGENCY SAFETY 56 4.1 Introduction 56 4.2 Rights, duties and responsibilities of employers and workers during outbreak and emergencies 57 4.3 Strategies and tools for protecting occupational safety and health in emergencies and outbreaks 58 4.4 Occupational safety and health controls 61 4.5 Conclusion of the chapter 4 62 CONCLUSION 64 REFERENCES 65 ANNEXE

ANALYSIS OF DATA & COMPUTER NETWORKS IN STUDENTS' RESIDENTIAL AREA IN UNIVERSITI TEKNOLOGI PETRONAS

In Universiti Teknologi Petronas (UTP), most of the students depend on the Internet and computer network connection to gain academics information and share educational resources. Even though the Internet connections and computers networks are provided, the service always experience interruption, such as slow Internet access, viruses and worms distribution, and network abuse by irresponsible students. Since UTP organization keeps on expanding, the need for a better service in UTP increases. Several approaches were put into practice to address the problems. Research on data and computer network was performed to understand the network technology applied in UTP. A questionnaire forms were distributed among the students to obtain feedback and statistical data about UTP's network in Students' Residential Area. The studies concentrate only on Students' Residential Area as it is where most of the users reside. From the survey, it can be observed that 99% of the students access the network almost 24 hours a day. In 2005, the 2 Mbps allocated bandwidth was utilized 100% almost continuously but in 2006, the bottleneck of Internet access has reduced significantly since the bandwidth allocated have been increased to 8 Mbps. Server degradation due to irresponsible acts by users also adds burden to the main server. In general, if the proposal to ITMS (Information Technology & Media Services) Department for them to improve their Quality of Service (QoS) and established UTP Computer Emergency Response Team (UCert), most of the issues addressed in this report can be solved