No description available.

Packet loss affects the ability of the network to satisfy the needs of its users. Packet loss can occur because of either congestion in the network, or because of transmission errors. It is important to reduce packet loss because applications such as real-time application and TCP-based applications are both sensitive to packet loss. The network should support some mechanism for reducing the loss experienced by its applications. This thesis presents a method for incorporating loss measurements into the Cognitive Packet Network. The idea of a Cumulative Loss is considered) which is defined as the loss from the source to the destination through the next hop. In addi- tion, a method is presented that allows for the combination of loss and delay as QoS constraints. These modifications are then tested to support their implementation.

M.Comm. / This study was conducted with the intent of understanding and evaluating the commercial use and possibilities that the Internet offers, as well as the strategic approach businesses should take when commencing with electronic commerce on the Internet. The potential value of Intranets and Extranets has also been examined briefly. The Internet is a very useful mechanism for marketing as well as sales of products or services on a domestic or international basis. Various other commercial possibilities and uses exist for the Internet, as well as for its derivatives — the Intranet and Extranet. In the fiercely competitive market of today, companies research, develop and invest resources in various methods and tools in the hope to gain competitive advantage over their rivals. The Internet, Intranet and Extranet, used in isolation or conjunction, pose an extremely attractive alternative to gaining competitive advantage in a specific sector or market niche.The success of the Internet as a business tool depends directly on the overall business strategy that is driving the approach. For optimum success the main business strategy must be aligned with the Information Technology Strategy, and especially include thorough consideration as well as planning when implementing the Internet or one of its derivatives as a business tool.

published_or_final_version / abstract / Electrical and Electronic Engineering / Master / Master of Philosophy

published_or_final_version / abstract / Electrical and Electronic Engineering / Master / Master of Philosophy

This dissertation describes the analysis, design, and implementation of a session level communication system referred to as PLEXNET. PLEXNET was developed specifically to provide communication services required by Computer Supported Cooperative Work (CSCW) applications but which are not currently available as part of commercially available LAN products. CSCW services include such things as: reliable broadcast communications, dynamic multicasting, and message queuing. Analysis of CSCW networking requirements entailed: reviewing CSCW applications and communications systems; synthesizing a data exchange model for collaborative tools; and defining a target system (PC-LAN). PLEXNET design provides a discussion of: networking tradeoffs, the relationship between PLEXNET and NETBIOS, PLEXNET queue structure, and PLEXNET implementation details. The design and implementation of PLEXNET were validated by performing discrete event simulations comparing response times and resource utilization for three communication paradigms and by developing four collaborative applications which employ PLEXNET for data communications. These applications are: Multi-User LAN Editor, Electronic Discussion System, Contracts Procurement, and Video Switcher.

No description available.

The description of a Network Management Package (NMP) for Packet Communications Units (PCUs) in a Local Area Network (LAN) is presented. The LAN consists of a Sytek LocalNet 20, a Sytek System 2000, a Sytek System 6000, and a Concord Data Systems Token/Net. The NMP accesses and controls the local and remote PCUs on the networks. The communication interface software module is responsible for opening and closing the session between the PC and PCU ports. The NMP supports a set of operations used by a network manager to control and manage the network PCUs. The user uses the NMP to integrate each PCU and check and set its attributes. The NMP was developed to run in the Computer Engineering Research Laboratory and in the University of Arizona broadband cable plant. The NMP allows different PCUs (local or remote) to check and modify PCU's attributes while users work on their own PCUs. (Abstract shortened with permission of author.)

Approved for public release, distribution unlimited / The progression of technology is continuous and the technology that drives interpersonal communication is not an exception. Recent technology advancements in the areas of multicast, firewalls, encryption techniques, and bandwidth availability have made the next level of interpersonal communication possible. This thesis answers why collaborative environments are important in today's online productivity. In doing so, it gives the reader a comprehensive background in distributed collaborative environments, answers how collaborative environments are employed in the Department of Defense and industry, details the effects network security has on multicast protocols, and compares collaborative solutions with a focus on security. The thesis ends by providing a recommendation for collaborative solutions to be utilized by NPS/DoD type networks. Efficient multicast collaboration, in the framework of security is a secondary focus of this research. As such, it takes security and firewall concerns into consideration while comparing and contrasting both multicast-based and non-multicast-based collaborative solutions.

D. Litt. et Phil. / Today, more and more organisations are adopting the use of the Internet and webbased technologies in the management of and provision of access to information and knowledge resources and services in digital formats. However, it appears that innovative use of the web is more pronounced in corporate organisations. For example, corporate organisations are using portals or sophisticated websites to conduct electronic commerce via the web and provide access to both internal and external information resources and services, accessed via the Internet, intranets, and extranets. The view of the researcher is that innovative use of the Internet and web-based technologies, such as portals, should not be the domain of the corporate world alone. The focus of this thesis is, therefore, to establish the potential application possibilities of portals in other types of organisations, especially agricultural research organisations in the Southern African Development Community (SADC) region. The main research problem addressed in this thesis was What is the nature and application possibility of agricultural information portals in the provision of webbased, value-added information services for researchers? To address the above research problem, literature relating to the historical development of the Internet and the World Wide Web, intranet and extranet applications in organisations, as well as portals and their applications, was reviewed. In addition, a study was made of international trends regarding the provision of access to digital agricultural information resources and services via the web, and a questionnaire survey was conducted to establish whether it was necessary to use portals to provide access to digital-based agricultural information resources and services in agricultural research organisations in the SADC region. ii Resulting from the literature reviews, the study of websites of international agricultural organisations, and the survey on the need for portals in agricultural research organisations in the SADC region, the study established that: · There are several potential applications of portals in agricultural research organisations. This led to the definition of the nature and major components of the type of portal that could serve the needs of researchers in agricultural research organisations. · There is a need for portals in agricultural research organisations in the SADC region. The current use of the web in these organisations in the region is largely limited to the development of brochureware types of websites, providing access to information contained in the organisations’ brochures. Therefore, there is need to upgrade from basic Web sites to advanced sites or portals, and the study concluded that in this regard there is a need for clear guidelines to assist agricultural research organisations to plan the deployment of their information portals. Currently, most organisations are using ad hoc approaches when developing their Web sites. The dissertation, furthermore, develops the definition of an agricultural information portal as a web-based application that is accessed via the intranet or extranet and provides a personalised and adaptive interface that enables agricultural researchers to discover, track, and interact with colleagues and other people, software applications, information resources, services and tools relevant to their research interests and work. Taking into account the major components and definition of an agricultural information portal, the study proposes guidelines for use in planning the deployment of portals in agricultural research organisations. The proposed guidelines are independent of specific portal design or development methodology, application domains, and techniques.