On the management and performance of a class of local area networks

This dissertation is concerned with the management and performance issues of those register-insertion (R-I) ring type local area networks (LANs) which employ the message removal by destination node protocol. A typical example of such a network is the Distributed Loop Computer Network (DLCN). developed by Liu et al for fundamental research in the field of distributed computing. After considering the management issues of low cost R-J LANs. the research deals with performance analysis of the dynamically reconfigurable register-insertion (DRR) network. In the first part of this research. a set of management functions is identified which are desirable and can be provided economically by a low cost LAN. A unique feature of the DLCN is that messages are removed from the network by the destination node. that is. messages do not travel whole of the loop. Therefore. it is not possible for a special control node to monitor the data traffic on the network without providing support functionality in each network access unit (NAU). The minimum functionality which must be provided in each NAU is identified in the thesis. A skeleton network was implemented to verify the feasibility of the proposed scheme. A paper describing the findings of this research was published and is reproduced as appendix A. In the second part of this research. a new feature of the DLCN network is introduced. namely. that the performance of a network employing removal by destination protocol can be improved by reconfiguring the network in a particular way. A methodology to find the optimal configuration is developed and is shown. by worked examples. to lead to improved performance. The findings of this research are particularly applicable to the dynamically reconfigurable register-insertion (DRR) network. A paper dealing with the optimisation of a hypothetical fully connected DRR network has been accepted for publication. Another paper. which considers the general case of less than fully connected DRR networks. is to be published. Both papers are reproduced as append ices Band C. Finally. a performance study of the ORR network is undertaken. As there seems to be no published attempt at formal analysis or simulation of a ORR network. a survey of literature dealing with performance study of the basic OLeN is performed. A simulation model of the DRR was then developed and implemented to verify the results arrived at in the previous section. Later. a queueing model of the DRR network. based on the work of Bux and Schlatter [7] is developed and analysed. Both simulation and analysis support the claim that the performance of a DRR network can be improved by adopting the configuration strategy developed in this thesis

A distributed local computer network : FISHNET (Facilities Integrated in a Shared Habitat NETwork)

FISHNET (Facilities Integrated in a Shared Habitat) is a communication subnet architecture utilizing a hybrid application of point-topoint and broadcast communications to achieve a high degree of network performance. This objective is achieved through utilizing a dual bus structure: a data bus and a control bus. The data bus consists of a set of uni- or bidirectional direct links connecting unique pairs of nodes. Data is transfered via an arbitrary connection pattern of links dynamically established between network nodes by circuit switching. The control bus is a common bus on which all nodes may transmit data, receive data, and monitor control and acknowledgement responses of other nodes via message switching. A fully distributed routing and control algorithm allocates communicationresources to communicating nodes. FISHNET offers an environment in which the communication structure may easily be incrementally modified (and improved) by insertion and deletion of additional networkcomponents. FISHNET has the ability to sense system faults and modify routing procedures via an adaptive learning control. Hence, link or node faults will not terminate all network operations. FISHNET performance has been simulated and found to offer performanceimprovement over the centralized version of FISHNET (i.e. Jafari Loop [JAFA 77]), the Newhall Loop [FARM 69], Pierce Loop [PIER 72a], and DLCN [REAM 761.FISHNET (Facilities Integrated in a Shared Habitat) is a communication subnet architecture utilizing a hybrid application of point-topoint and broadcast communications to achieve a high degree of network performance. This objective is achieved through utilizing a dual bus structure: a data bus and a control bus. The data bus consists of a set of uni- or bidirectional direct links connecting unique pairs of nodes. Data is transfered via an arbitrary connection pattern of links dynamically established between network nodes by circuit switching. The control bus is a common bus on which all nodes may transmit dat

Local computer networks :a study

This thesis examines the principles underlying the design of local computer networks. It then reviews the features of several existing long-haul and local networks. The design and construction of Bassernet - a network using an Ethernet type protocol on a loop topology is described. Measurements of the performance of Bassernet are presented and commented on. Finally, some speculations are made on the future of the Bassernet network

DECENTRALIZED CONTROL OF DISTRIBUTED PROCESSING SYSTEMS

This thesis presents a methodology for implementing decentralized scheduling for distributed systems. The environment in which the controlling entities make decisions is stochastic and can be described as uncertain since each entity may have a different view of the system state. As a consequence, these entities may make inconsistent decisions. The methodology is based on defining the system state as a set of distributions and using a queueing model to predict the future behaviour of the system. The predicted state is used to schedule the individual job tasks based on minimum predicted job response time. A hypothetical real system is simulated. The methodology was tested using different queueing models and under different environments. An evaluation of the proposed technique using the simulation results indicates a consistent performance improvement over the no network case. Suggestions for extending this research are also presented

Performance of buffer insertion LANs

This thesis presents an evaluation of the performance of some ring local area network protocols, specifically the buffer insertion ring and the token ring. Both dual and single versions of each are considered, and performance statistics are obtained by measurements on real networks, by mathematical analysis, and by computer simulation. New packet routing protocols for dual contrarotating buffer insertion and token ring networks are described and their performance is examined. It is found that, due to the bandwith reuse properties of the routing methods, maximum throughputs of 800% and 200% are achievable, for the dual buffer insertion ring and the dual token ring respectively

The integrity of serial data highway systems

The Admiralty Surface Weapons Establishment (ASWE) have developed a Local Area Network System. This thesis describes the development of a replacement for this LAN system, based around 16 bit microprocessor hosts, as opposed to the minicomputers currently used. This change gave a substantial reduction in size, and allowed the new system to be installed on a ship and tested under operational conditions. Analysis of the data collected during the tests gave performance information on the ASWE system. The performance of this LAN is compared to that of other leading types of LAN. The design of a portable network controller/ monitor unit is presented, which may be manufactured as a standard controller for the ASWE Serial Highway

Pipeline rings and integrated services rings.

Wong, Po-Choi.Summary in Chinese.Thesis (Ph.D.)--Chinese University of Hong Kong, 1989.Bibliography: leaves 156-164