M.Com. (Computer Auditing) / Intranets and related technology, can be used to solve many problems in the local computing environment. But the use of the Intranet and the related technology also raises several control concerns. Because of the increased use of Intranets within the business environment, the internal control related to the Intranet has become an issue that needs to be addressed by management and the auditor. Computerization in the accounting environment has made it virtually impossible to audit around the computer. It is therefore essential that the auditor, and more specifically the computer auditor, should assess the influence of the Intranet on the audit objectives. The objective of this short dissertation is to evaluate the influence of Intranet technology on the audit objectives (within the Intranet's different spheres of application) in terms of the risks posed for the auditor and management. It was also aimed at identifying the security risks in relationship with the audit objectives...

Ad-Hoc mesh networks offer great promise. Low-cost ad-hoc mesh networks can be built using popular IEEE 802.11 equipment, but such networks are unable to guarantee each node a fair share of bandwidth. Furthermore, hidden node problems cause collisions which can cripple the throughput of a network. This research proposes a novel mechanism which is able to overcome hidden node problems and provide fair bandwidth sharing among nodes on ad-hoc 802.11 networks, and can be implemented on existing network devices. The scheme uses TDM (time division multiplexing) with slot reservation. A distributed beacon packet latency measurement mechanism is used to achieve node synchronisation. The distributed nature of the mechanism makes it applicable to ad-hoc 802.11 networks, which can either grow or fragment dynamically.

Discusses the development of WebSAT (Web-based systems administration tool), a computer network tool that allows systems administrators to create and delete accounts, disable and enable existing accounts, manage disk space conveniently, monitor the status of all network printers, and monitor network security. The WebSAT application was implemented using PHP, a server-side embedded scripting language, with a MySQL database.

With network enabled consumer devices becoming increasingly popular, the number of connected devices and available services is growing considerably - with the number of connected devices es- timated to surpass 15 billion devices by 2015. In this increasingly large and dynamic environment it is important that users have a comprehensive, yet efficient, mechanism to discover services. Many existing wide-area service discovery mechanisms are centralised and do not scale to large numbers of users. Additionally, centralised services suffer from issues such as a single point of failure, high maintenance costs, and difficulty of management. As such, this Thesis seeks a Peer to Peer (P2P) approach. Distributed Hash Tables (DHTs) are well known for their high scalability, financially low barrier of entry, and ability to self manage. They can be used to provide not just a platform on which peers can offer and consume services, but also as a means for users to discover such services. Traditionally DHTs provide a distributed key-value store, with no search functionality. In recent years many P2P systems have been proposed providing support for a sub-set of complex query types, such as keyword search, range queries, and semantic search. This Thesis presents a novel algorithm for performing any type of complex query, from keyword search, to complex regular expressions, to full-text search, over any structured P2P overlay. This is achieved by efficiently broadcasting the search query, allowing each peer to process the query locally, and then efficiently routing responses back to the originating peer. Through experimentation, this technique is shown to be successful when the network is stable, however performance degrades under high levels of network churn. To address the issue of network churn, this Thesis proposes a number of enhancements which can be made to existing P2P overlays in order to improve the performance of both the existing DHT and the proposed algorithm. Through two case studies these enhancements are shown to improve not only the performance of the proposed algorithm under churn, but also the performance of traditional lookup operations in these networks.

Enhancement of network data-plane functionality is an open problem that has recently gained momentum. Addition and programmability of new functions inside the network data-plane to enable high speed, complex network functions with minimum resource utilization, is main focus of this thesis. In this work, we look at different levels of the network data-plane design and using network virtualization and software defined networking we propose data-plane enhancements to achieve these goals. This thesis is divided into two parts, in first part we take a ground up approach where we focus our attention at the fast path packet processing. Using hardware and software based network virtualization we show how hardware and software based network switches can be designed to achieve above mentioned goals. We then present a switch design to quickly add these custom fast path packet processors to the network data-plane using software defined networking. In second part of this thesis we take a top to bottom approach where we present a programming abstraction for network operators and a network function deployment system for this programming abstraction. We use network virtualization and software defined networking to introduce new functions inside the network data-plane while alleviating the network operators of the deployment details and minimizing the network resource utilization.

published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy

published_or_final_version / Computer Science and Information Systems / Master / Master of Philosophy

published_or_final_version / Computer Science and Information Systems / Master / Master of Philosophy

published_or_final_version / Computer Science / Master / Master of Philosophy

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