983 research outputs found
Performance analysis of Gb/s WDM FDDI network
In this paper, we propose a time-token multi-Gb/s Wavelength Division Multiplexing Fibre Distributed Data Interface (WDM/FDDI) architecture and examine its throughput efficiency and delay under heavy load for different network configuration using discrete event simulator
Hybrid Wavelength Routed and Optical Packet Switched Ring Networks for the Metropolitan Area Network
Performance Improvements for FDDI and CSMA/CD Protocols
The High-Performance Computing Initiative from the White House Office of Science and Technology Policy has defined 20 major challenges in science and engineering which are dependent on the solutions to a number of high-performance computing problems. One of the major areas of focus of this initiative is the development of gigabit rate networks to be used in environments such as the space station or a National Research and Educational Network (NREN).
The strategy here is to use existing network designs as building blocks for achieving higher rates, with the ultimate goal being a gigabit rate network. Two strategies which contribute to achieving this goal are examined in detail.1
FDDI2 is a token ring network based on fiber optics capable of a 100 Mbps rate. Both media access (MAC) and physical layer modifications are considered. A method is presented which allows one to determine maximum utilization based on the token-holding timer settings. Simulation results show that employing the second counter-rotating ring in combination with destination removal has a multiplicative effect greater than the effect which either of the factors have individually on performance. Two 100 Mbps rings can handle loads in the range of 400 to 500 Mbps for traffic with a uniform distribution and fixed packet size. Performance is dependent on the number of nodes, improving as the number increases. A wide range of environments are examined to illustrate robustness, and a method of implementation is discussed
Design And Analysis Of a Multi-channel Optical Fibre Lan Based On Modified Csma/cd Protocol
Nowadays, optical communication is widely employed by telecommunication
providers in the whole world due to its ability to support high bit rate applications. The
urge to provide end-to-end fibre connectivity arises to overcome the bottleneck problem
that occurs when packets are transmitted on the slower speed medium such as copper. In
optical transmission, bandwidth utilisation can be improved further by using multiple
wavelengths or channels in a single fibre.
This thesis discusses the implementation of multiple wavelengths technique for
Local Area Network (LAN) environment. It proposes a new Ethernet-based protocol that
uses multiple wavelengths for transmission, which runs on a single fibre. Ethernet/IEEE
802.3 is chosen because of its widespread employment in today's network and the
ability of extending the transmission rate up to gigabit transmission. Even though light
does not collide with each other, receiver contention might occur if more than one signal
arrives at the receiver at the same time. Therefore, some arbitration mechanism is
needed to synchronise the transmission and the tuning time of the respective transmitter and receiver. The proposed design is based on the physical bus topology with n number
of connected nodes and m number of operating wavelengths. All nodes are able to listen
to all wavelengths. A fast control unit is used, which is responsible for packet
scheduling.
The packets are scheduled based on a pre-computed time. Both transmitter and
receiver will be asked to tune to the· allocated wavelength. The transmitter can start
transmitting and the receiver will start tuning at a specified time. Control packets are
used for handshaking purposes. The main operation is placed at the control unit so that
no added complexity is experienced by the receiver. Thus, this technique further reduces
the cost. A suitable range of channels is obtained from the result. The network
performance is evaluated against several design parameters by comparing the
performance of each channel. The result shows a significant improvement whereby the
throughput and efficiency are increased and average delay is minimised compared to the
conventional system
Simulation analysis of FDDI network using NETWORK II.5 software package
In recent years, one of the most exciting advances in media has been the use of fiber optics in LANs. The bandwidth provided by Fiber Optic Technology has drastically increased the number of new applications that can be supported by communication networks. In order to support a variety of services, in 1986, the American National Standard Institute (ANSI) Accredited Standards Committee (ASC) X3, and the ASC X3T9.5 Task Group developed a new standard; the Fiber Distributed Data Interface (FDDI) [1]. This is a high speed (100 Mbps) optical communication network based on a token passing mode of operation. The Medium Access Control (MAC) Protocol selected for this network attempts to provide priority services, as well as bounded delay transmission for real time applications [2].
This thesis presents results for the Voice-Data performance of the Medium Access Control (MAC) protocol, selected for the FDDI network, using the NETWORK 11.5 [6] software package. This protocol can provide priority services to different types of traffic, as well as guarantee bounded delays for real-time applications. The effect of various system parameters on performance is investigated
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