An investigation into some critical computer networking parameters : Internet addressing and routing
- Authors: Isted, Edwin David
- Date: 1996
- Subjects: Computer networks , Internet , Electronic mail systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4608 , http://hdl.handle.net/10962/d1004874 , Computer networks , Internet , Electronic mail systems
- Description: This thesis describes the evaluation of several proposals suggested as replacements for the currenT Internet's TCPJIP protocol suite. The emphasis of this thesis is on how the proposals solve the current routing and addressing problems associated with the Internet. The addressing problem is found to be related to address space depletion, and the routing problem related to excessive routing costs. The evaluation is performed based on criteria selected for their applicability as future Internet design criteria. AIl the protocols are evaluated using the above-mentioned criteria. It is concluded that the most suitable addressing mechanism is an expandable multi-level format, with a logical separation of location and host identification information. Similarly, the most suitable network representation technique is found to be an unrestricted hierarchical structure which uses a suitable abstraction mechanism. It is further found that these two solutions could adequately solve the existing addressing and routing problems and allow substantial growth of the Internet.
- Full Text:
- Date Issued: 1996
An investigation into some critical computer networking parameters : Internet addressing and routing
- Authors: Isted, Edwin David
- Date: 1996
- Subjects: Computer networks , Internet , Electronic mail systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4608 , http://hdl.handle.net/10962/d1004874 , Computer networks , Internet , Electronic mail systems
- Description: This thesis describes the evaluation of several proposals suggested as replacements for the currenT Internet's TCPJIP protocol suite. The emphasis of this thesis is on how the proposals solve the current routing and addressing problems associated with the Internet. The addressing problem is found to be related to address space depletion, and the routing problem related to excessive routing costs. The evaluation is performed based on criteria selected for their applicability as future Internet design criteria. AIl the protocols are evaluated using the above-mentioned criteria. It is concluded that the most suitable addressing mechanism is an expandable multi-level format, with a logical separation of location and host identification information. Similarly, the most suitable network representation technique is found to be an unrestricted hierarchical structure which uses a suitable abstraction mechanism. It is further found that these two solutions could adequately solve the existing addressing and routing problems and allow substantial growth of the Internet.
- Full Text:
- Date Issued: 1996
The analysis of a computer music network and the implementation of essential subsystems
- Authors: Wilks, Antony John
- Date: 1995
- Subjects: Computer networks , Computer music , MIDI (Standard)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4666 , http://hdl.handle.net/10962/d1006682 , Computer networks , Computer music , MIDI (Standard)
- Description: The inability to share resources in commercial and institutional computer music studios results in non-optimal resource utilisation. The use of computers to process, store and communicate data can be extended within these studios, to provide the capability of sharing resources amongst their users. This thesis describes a computer music network which was designed for this purpose. Certain devices had to be custom built for the implementation of the network. The thesis discusses the design and construction of these devices.
- Full Text:
- Date Issued: 1995
- Authors: Wilks, Antony John
- Date: 1995
- Subjects: Computer networks , Computer music , MIDI (Standard)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4666 , http://hdl.handle.net/10962/d1006682 , Computer networks , Computer music , MIDI (Standard)
- Description: The inability to share resources in commercial and institutional computer music studios results in non-optimal resource utilisation. The use of computers to process, store and communicate data can be extended within these studios, to provide the capability of sharing resources amongst their users. This thesis describes a computer music network which was designed for this purpose. Certain devices had to be custom built for the implementation of the network. The thesis discusses the design and construction of these devices.
- Full Text:
- Date Issued: 1995
An empirical, in-depth investigation into service creation in H.323 Version 4 Networks
- Authors: Penton, Jason Barry
- Date: 2003 , 2013-05-24
- Subjects: Computer programming , Computer networks , Computer network protocols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4681 , http://hdl.handle.net/10962/d1007637 , Computer programming , Computer networks , Computer network protocols
- Description: Over the past few years there has been an increasing tendency to carry voice on IP networks as opposed to the PSTN and other switched circuit networks. Initially this trend was favoured due to reduced costs but occurred at the expense of sacrificing the quality of the voice communications. Switched circuit networks have therefore remained the preferred carrier-grade voice communication network, but this is again changing. The advancement in improved quality of service (QoS) of real-time traffic on the IP network is a contributing factor to the anticipated future of the IP network supplying carrier-grade voice communications. Another contributing factor is the possibility of creating a new range of innovative, state-of-the-art telephony and communications services that acquire leverage through the intelligence and flexibility of the IP network. The latter has yet to be fully explored. Various protocols exist that facilitate the transport of voice and other media on IP networks. The most well known and widely supported of these is H.323. This work presents and discusses H.323 version 4 service creation. The work also categorises the various H.323 services and presents the mechanisms provided by H.323 version 4 that have facilitated the development of the three services I have developed, EmailReader, Telgo323 and CANS.
- Full Text:
- Date Issued: 2003
- Authors: Penton, Jason Barry
- Date: 2003 , 2013-05-24
- Subjects: Computer programming , Computer networks , Computer network protocols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4681 , http://hdl.handle.net/10962/d1007637 , Computer programming , Computer networks , Computer network protocols
- Description: Over the past few years there has been an increasing tendency to carry voice on IP networks as opposed to the PSTN and other switched circuit networks. Initially this trend was favoured due to reduced costs but occurred at the expense of sacrificing the quality of the voice communications. Switched circuit networks have therefore remained the preferred carrier-grade voice communication network, but this is again changing. The advancement in improved quality of service (QoS) of real-time traffic on the IP network is a contributing factor to the anticipated future of the IP network supplying carrier-grade voice communications. Another contributing factor is the possibility of creating a new range of innovative, state-of-the-art telephony and communications services that acquire leverage through the intelligence and flexibility of the IP network. The latter has yet to be fully explored. Various protocols exist that facilitate the transport of voice and other media on IP networks. The most well known and widely supported of these is H.323. This work presents and discusses H.323 version 4 service creation. The work also categorises the various H.323 services and presents the mechanisms provided by H.323 version 4 that have facilitated the development of the three services I have developed, EmailReader, Telgo323 and CANS.
- Full Text:
- Date Issued: 2003
Correlation and comparative analysis of traffic across five network telescopes
- Nkhumeleni, Thizwilondi Moses
- Authors: Nkhumeleni, Thizwilondi Moses
- Date: 2014
- Subjects: Sensor networks , Computer networks , TCP/IP (Computer network protocol) , Computer networks -- Management , Electronic data processing -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4693 , http://hdl.handle.net/10962/d1011668 , Sensor networks , Computer networks , TCP/IP (Computer network protocol) , Computer networks -- Management , Electronic data processing -- Management
- Description: Monitoring unused IP address space by using network telescopes provides a favourable environment for researchers to study and detect malware, worms, denial of service and scanning activities. Research in the field of network telescopes has progressed over the past decade resulting in the development of an increased number of overlapping datasets. Rhodes University's network of telescope sensors has continued to grow with additional network telescopes being brought online. At the time of writing, Rhodes University has a distributed network of five relatively small /24 network telescopes. With five network telescope sensors, this research focuses on comparative and correlation analysis of traffic activity across the network of telescope sensors. To aid summarisation and visualisation techniques, time series' representing time-based traffic activity, are constructed. By employing an iterative experimental process of captured traffic, two natural categories of the five network telescopes are presented. Using the cross- and auto-correlation methods of time series analysis, moderate correlation of traffic activity was achieved between telescope sensors in each category. Weak to moderate correlation was calculated when comparing category A and category B network telescopes' datasets. Results were significantly improved by studying TCP traffic separately. Moderate to strong correlation coefficients in each category were calculated when using TCP traffic only. UDP traffic analysis showed weaker correlation between sensors, however the uniformity of ICMP traffic showed correlation of traffic activity across all sensors. The results confirmed the visual observation of traffic relativity in telescope sensors within the same category and quantitatively analysed the correlation of network telescopes' traffic activity.
- Full Text:
- Date Issued: 2014
- Authors: Nkhumeleni, Thizwilondi Moses
- Date: 2014
- Subjects: Sensor networks , Computer networks , TCP/IP (Computer network protocol) , Computer networks -- Management , Electronic data processing -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4693 , http://hdl.handle.net/10962/d1011668 , Sensor networks , Computer networks , TCP/IP (Computer network protocol) , Computer networks -- Management , Electronic data processing -- Management
- Description: Monitoring unused IP address space by using network telescopes provides a favourable environment for researchers to study and detect malware, worms, denial of service and scanning activities. Research in the field of network telescopes has progressed over the past decade resulting in the development of an increased number of overlapping datasets. Rhodes University's network of telescope sensors has continued to grow with additional network telescopes being brought online. At the time of writing, Rhodes University has a distributed network of five relatively small /24 network telescopes. With five network telescope sensors, this research focuses on comparative and correlation analysis of traffic activity across the network of telescope sensors. To aid summarisation and visualisation techniques, time series' representing time-based traffic activity, are constructed. By employing an iterative experimental process of captured traffic, two natural categories of the five network telescopes are presented. Using the cross- and auto-correlation methods of time series analysis, moderate correlation of traffic activity was achieved between telescope sensors in each category. Weak to moderate correlation was calculated when comparing category A and category B network telescopes' datasets. Results were significantly improved by studying TCP traffic separately. Moderate to strong correlation coefficients in each category were calculated when using TCP traffic only. UDP traffic analysis showed weaker correlation between sensors, however the uniformity of ICMP traffic showed correlation of traffic activity across all sensors. The results confirmed the visual observation of traffic relativity in telescope sensors within the same category and quantitatively analysed the correlation of network telescopes' traffic activity.
- Full Text:
- Date Issued: 2014
An investigation of a framework to evaluate computer supported collaborative work
- Beauvais, Erik Alexander Maoui
- Authors: Beauvais, Erik Alexander Maoui
- Date: 1999
- Subjects: Computer networks , Teams in the workplace -- Data processing , Technology -- Data processing , Information technology -- Economic aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1135 , http://hdl.handle.net/10962/d1002763 , Computer networks , Teams in the workplace -- Data processing , Technology -- Data processing , Information technology -- Economic aspects
- Description: Rapidly changing technology constantly modifies the way in which tasks are conceived and executed. Furthermore, leading organisations also encourage the use of new technology to support and establish innovative ways of doing business. For example, technology has helped to drive the globalization and tighter integration of world markets. This has facilitated, and even necessitated, business organisations to compete for work across national borders. For geographically dispersed organisations, collaboration has become critical. But this has presented time and space work complexities. Communication and collaboration technologies, for example, are needed to support such emerging co-operative business practices. The short development cycle of technology, communication and collaborative technologies included, leaves little time for testing and less for understanding the impact of new technology. To compound the problem, no established formulae exist for matching technology with work: over-investment is a waste of resources, while under-investment could lead to work failure. This research proposes a framework to assist organisations in selecting the appropriate level of technology with the work required. In this study, the methodology developed by the Evaluation Working Group, the DARPA Intelligent Collaboration and Visualization program is extended, and a matrix framework is constructed which compares the success of generic work tasks against a range of technology resources. The framework is tested using a low resource configuration, with selected work task types generally found in software development. (The Joint Application Development (JAD) methodology for software development is used as the contextual basis of the experiment.) All activities are evaluated according to selected measure components of success. A collection of research methods known as ethnography is used to examine and test the framework. Methods employed include questionnaires, interviews, interaction analysis and ethnomethodology. The results indicate that even at a low resource level, given selected criteria, collaborative technology successfully supports certain collaborative work activities. Findings also indicate that softer people issues require much more attention in order for technology to support natural collaborative work. Finally, user defined parameter testing has indicated that the framework functions as expected and designed.
- Full Text:
- Date Issued: 1999
- Authors: Beauvais, Erik Alexander Maoui
- Date: 1999
- Subjects: Computer networks , Teams in the workplace -- Data processing , Technology -- Data processing , Information technology -- Economic aspects
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:1135 , http://hdl.handle.net/10962/d1002763 , Computer networks , Teams in the workplace -- Data processing , Technology -- Data processing , Information technology -- Economic aspects
- Description: Rapidly changing technology constantly modifies the way in which tasks are conceived and executed. Furthermore, leading organisations also encourage the use of new technology to support and establish innovative ways of doing business. For example, technology has helped to drive the globalization and tighter integration of world markets. This has facilitated, and even necessitated, business organisations to compete for work across national borders. For geographically dispersed organisations, collaboration has become critical. But this has presented time and space work complexities. Communication and collaboration technologies, for example, are needed to support such emerging co-operative business practices. The short development cycle of technology, communication and collaborative technologies included, leaves little time for testing and less for understanding the impact of new technology. To compound the problem, no established formulae exist for matching technology with work: over-investment is a waste of resources, while under-investment could lead to work failure. This research proposes a framework to assist organisations in selecting the appropriate level of technology with the work required. In this study, the methodology developed by the Evaluation Working Group, the DARPA Intelligent Collaboration and Visualization program is extended, and a matrix framework is constructed which compares the success of generic work tasks against a range of technology resources. The framework is tested using a low resource configuration, with selected work task types generally found in software development. (The Joint Application Development (JAD) methodology for software development is used as the contextual basis of the experiment.) All activities are evaluated according to selected measure components of success. A collection of research methods known as ethnography is used to examine and test the framework. Methods employed include questionnaires, interviews, interaction analysis and ethnomethodology. The results indicate that even at a low resource level, given selected criteria, collaborative technology successfully supports certain collaborative work activities. Findings also indicate that softer people issues require much more attention in order for technology to support natural collaborative work. Finally, user defined parameter testing has indicated that the framework functions as expected and designed.
- Full Text:
- Date Issued: 1999
Bandwidth management and monitoring for IP network traffic : an investigation
- Authors: Irwin, Barry Vivian William
- Date: 2001
- Subjects: TCP/IP (Computer network protocol) , Computer networks , Electronic data processing -- Management , Computer networks -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4624 , http://hdl.handle.net/10962/d1006492 , TCP/IP (Computer network protocol) , Computer networks , Electronic data processing -- Management , Computer networks -- Management
- Description: Bandwidth management is a topic which is often discussed, but on which relatively little work has been done with regard to compiling a comprehensive set of techniques and methods for managing traffic on a network. What work has been done has concentrated on higher end networks, rather than the low bandwidth links which are commonly available in South Africa and other areas outside the United States. With more organisations increasingly making use of the Internet on a daily basis, the demand for bandwidth is outstripping the ability of providers to upgrade their infrastructure. This resource is therefore in need of management. In addition, for Internet access to become economically viable for widespread use by schools, NGOs and other academic institutions, the associated costs need to be controlled. Bandwidth management not only impacts on direct cost control, but encompasses the process of engineering a network and network resources in order to ensure the provision of as optimal a service as possible. Included in this is the provision of user education. Software has been developed for the implementation of traffic quotas, dynamic firewalling and visualisation. The research investigates various methods for monitoring and management of IP traffic with particular applicability to low bandwidth links. Several forms of visualisation for the analysis of historical and near-realtime traffic data are also discussed, including the use of three-dimensional landscapes. A number of bandwidth management practices are proposed, and the advantages of their combination, and complementary use are highlighted. By implementing these suggested policies, a holistic approach can be taken to the issue of bandwidth management on Internet links.
- Full Text:
- Date Issued: 2001
- Authors: Irwin, Barry Vivian William
- Date: 2001
- Subjects: TCP/IP (Computer network protocol) , Computer networks , Electronic data processing -- Management , Computer networks -- Management
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4624 , http://hdl.handle.net/10962/d1006492 , TCP/IP (Computer network protocol) , Computer networks , Electronic data processing -- Management , Computer networks -- Management
- Description: Bandwidth management is a topic which is often discussed, but on which relatively little work has been done with regard to compiling a comprehensive set of techniques and methods for managing traffic on a network. What work has been done has concentrated on higher end networks, rather than the low bandwidth links which are commonly available in South Africa and other areas outside the United States. With more organisations increasingly making use of the Internet on a daily basis, the demand for bandwidth is outstripping the ability of providers to upgrade their infrastructure. This resource is therefore in need of management. In addition, for Internet access to become economically viable for widespread use by schools, NGOs and other academic institutions, the associated costs need to be controlled. Bandwidth management not only impacts on direct cost control, but encompasses the process of engineering a network and network resources in order to ensure the provision of as optimal a service as possible. Included in this is the provision of user education. Software has been developed for the implementation of traffic quotas, dynamic firewalling and visualisation. The research investigates various methods for monitoring and management of IP traffic with particular applicability to low bandwidth links. Several forms of visualisation for the analysis of historical and near-realtime traffic data are also discussed, including the use of three-dimensional landscapes. A number of bandwidth management practices are proposed, and the advantages of their combination, and complementary use are highlighted. By implementing these suggested policies, a holistic approach can be taken to the issue of bandwidth management on Internet links.
- Full Text:
- Date Issued: 2001
The determination of whether a Unified Communication System can be effective in supporting informal communication and collaboration in virtual teams
- Authors: Hill, Kyle
- Date: 2020
- Subjects: Telecommuting , Virtual work teams , Telecommunication systems , Computer networks
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146343 , vital:38517
- Description: The overall objective of the research is to determine whether a Unified Communication System intervention can be effective in supporting informal communication and collaboration in virtual teams. In so doing, this research is aimed at developing a current framework of critical success factors for facilitating informal collaboration and communication. As teams have evolved to the point where there is no longer a need for team members to be co-located, with a greater importance now being placed on how they collaborate, this framework will also highlight how it can support virtual teams due to the huge potential advantage they can provide to the organisation. A virtual communication and collaboration system will be selected based on the outputs of the current framework and interactions which occur through the system will be observed to provide quantitative and qualitative results. In conclusion, the research will suggest recommendations for the successful implementation of informal communication and collaboration technologies within the organisation. The research will also indicate to a limited degree, the impact of the implementation of these technologies, and the outcome for the organisation, whether positive or negative. Whilst conducting the research, it became apparent that while the UCS was capable of performing the processes and functions required, the individuals and teams engaging with the technology did not always make use of the full scope of the technology provided. Regardless, a UCS was observed to provide direct benefits to an organisation in increasing communication and collaboration in the organisation. These increases can be observed in both the physical and virtual sense. However, the converse is true for generating social capital which lead to the observation that there are a smaller number of interactions happening in the smaller teams, but these are of higher value when compared to the larger teams of this study. It is also clear that the larger a team becomes, the more the trend is to focus on adopting new technologies to make their roles more efficient. This adoption is not however translated into outputs such as social capital but is translated into stronger networks and the formation of new networks. It is also clear that most negative factors around the UCS are related to the respondent’s hardware rather than the solution itself. Cost reductions because of virtuality will also be observed and using the Developed Framework as a blue print, an organisation should be able to observe direct benefits for an organisation by being able to confirm the thesis of this research in that having a UCS intervention is effective in supporting informal communication and collaboration in virtual teams.
- Full Text:
- Date Issued: 2020
- Authors: Hill, Kyle
- Date: 2020
- Subjects: Telecommuting , Virtual work teams , Telecommunication systems , Computer networks
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/146343 , vital:38517
- Description: The overall objective of the research is to determine whether a Unified Communication System intervention can be effective in supporting informal communication and collaboration in virtual teams. In so doing, this research is aimed at developing a current framework of critical success factors for facilitating informal collaboration and communication. As teams have evolved to the point where there is no longer a need for team members to be co-located, with a greater importance now being placed on how they collaborate, this framework will also highlight how it can support virtual teams due to the huge potential advantage they can provide to the organisation. A virtual communication and collaboration system will be selected based on the outputs of the current framework and interactions which occur through the system will be observed to provide quantitative and qualitative results. In conclusion, the research will suggest recommendations for the successful implementation of informal communication and collaboration technologies within the organisation. The research will also indicate to a limited degree, the impact of the implementation of these technologies, and the outcome for the organisation, whether positive or negative. Whilst conducting the research, it became apparent that while the UCS was capable of performing the processes and functions required, the individuals and teams engaging with the technology did not always make use of the full scope of the technology provided. Regardless, a UCS was observed to provide direct benefits to an organisation in increasing communication and collaboration in the organisation. These increases can be observed in both the physical and virtual sense. However, the converse is true for generating social capital which lead to the observation that there are a smaller number of interactions happening in the smaller teams, but these are of higher value when compared to the larger teams of this study. It is also clear that the larger a team becomes, the more the trend is to focus on adopting new technologies to make their roles more efficient. This adoption is not however translated into outputs such as social capital but is translated into stronger networks and the formation of new networks. It is also clear that most negative factors around the UCS are related to the respondent’s hardware rather than the solution itself. Cost reductions because of virtuality will also be observed and using the Developed Framework as a blue print, an organisation should be able to observe direct benefits for an organisation by being able to confirm the thesis of this research in that having a UCS intervention is effective in supporting informal communication and collaboration in virtual teams.
- Full Text:
- Date Issued: 2020
Extending the reach of personal area networks by transporting Bluetooth communications over IP networks
- Authors: Mackie, David Sean
- Date: 2007 , 2007-03-29
- Subjects: Bluetooth technology , Communication -- Technological innovations , Communication -- Network analysis , TCP/IP (Computer network protocol) , Computer networks , Computer network protocols , Wireless communication systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4637 , http://hdl.handle.net/10962/d1006551 , Bluetooth technology , Communication -- Technological innovations , Communication -- Network analysis , TCP/IP (Computer network protocol) , Computer networks , Computer network protocols , Wireless communication systems
- Description: This thesis presents an investigation of how to extend the reach of a Bluetooth personal area network by introducing the concept of Bluetooth Hotspots. Currently two Bluetooth devices cannot communicate with each other unless they are within radio range, since Bluetooth is designed as a cable-replacement technology for wireless communications over short ranges. An investigation was done into the feasibility of creating Bluetooth hotspots that allow distant Bluetooth devices to communicate with each other by transporting their communications between these hotspots via an alternative network infrastructure such as an IP network. Two approaches were investigated, masquerading of remote devices by the local hotspot to allow seamless communications and proxying services on remote devices by providing them on a local hotspot using a distributed service discovery database. The latter approach was used to develop applications capable of transporting Bluetooth’s RFCOMM and L2CAP protocols. Quantitative tests were performed to establish the throughput performance and latency of these transport applications. Furthermore, a number of selected Bluetooth services were tested which lead us to conclude that most data-based protocols can be transported by the system.
- Full Text:
- Date Issued: 2007
- Authors: Mackie, David Sean
- Date: 2007 , 2007-03-29
- Subjects: Bluetooth technology , Communication -- Technological innovations , Communication -- Network analysis , TCP/IP (Computer network protocol) , Computer networks , Computer network protocols , Wireless communication systems
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4637 , http://hdl.handle.net/10962/d1006551 , Bluetooth technology , Communication -- Technological innovations , Communication -- Network analysis , TCP/IP (Computer network protocol) , Computer networks , Computer network protocols , Wireless communication systems
- Description: This thesis presents an investigation of how to extend the reach of a Bluetooth personal area network by introducing the concept of Bluetooth Hotspots. Currently two Bluetooth devices cannot communicate with each other unless they are within radio range, since Bluetooth is designed as a cable-replacement technology for wireless communications over short ranges. An investigation was done into the feasibility of creating Bluetooth hotspots that allow distant Bluetooth devices to communicate with each other by transporting their communications between these hotspots via an alternative network infrastructure such as an IP network. Two approaches were investigated, masquerading of remote devices by the local hotspot to allow seamless communications and proxying services on remote devices by providing them on a local hotspot using a distributed service discovery database. The latter approach was used to develop applications capable of transporting Bluetooth’s RFCOMM and L2CAP protocols. Quantitative tests were performed to establish the throughput performance and latency of these transport applications. Furthermore, a number of selected Bluetooth services were tested which lead us to conclude that most data-based protocols can be transported by the system.
- Full Text:
- Date Issued: 2007
Email meets issue-tracking: a prototype implementation
- Authors: Kwinana, Zukhanye N
- Date: 2006 , 2013-06-11
- Subjects: Microsoft Visual studio , Electronic mail systems , Computer networks , eXtreme programming , Computer software -- Development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4614 , http://hdl.handle.net/10962/d1005644 , Microsoft Visual studio , Electronic mail systems , Computer networks , eXtreme programming , Computer software -- Development
- Description: The use of electronic mail (email) has evolved from sending simple messages to task delegation and management. Most mail clients, however, have not kept up with the evolution and as a result have limited task management features available. On the other hand, while issue tracking systems offer useful task management functionality, they are not as widespread as emails and also have a few drawbacks. This thesis reports on the exploration of the integration of the ubiquitous nature of email with the task management features of issue-tracking systems. We explore this using simple ad-hoc as well as semi-automated tasks. With these two working together, tasks can be delegated from email clients without needing to switch between the two environments. It brings some of the benefits of issue tracking systems closer to our email users.The system is developed using Microsoft VisuaI Studio.NET. with the code written in C#. The eXtreme Programming (XP) methodology was used during the development of the proof-of-concept prototype that demonstrates the integration of the two environments, as we were faced at first with vague requirements bound to change, as we better understood the problem domain through our development. XP allowed us to skip an extended and comprehensive initial design process and incrementally develop the system, making refinements and extensions as we encountered the need for them. This alleviated the need to make upfront decisions that were based on minimal knowledge of what to expect during development. This thesis describes the implementation of the prototype and the decisions made with each step taken towards developing an email-based issue tracking system. With the two environments working together, we can now easily track issues from our email clients without needing to switch to another system. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2006
- Authors: Kwinana, Zukhanye N
- Date: 2006 , 2013-06-11
- Subjects: Microsoft Visual studio , Electronic mail systems , Computer networks , eXtreme programming , Computer software -- Development
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4614 , http://hdl.handle.net/10962/d1005644 , Microsoft Visual studio , Electronic mail systems , Computer networks , eXtreme programming , Computer software -- Development
- Description: The use of electronic mail (email) has evolved from sending simple messages to task delegation and management. Most mail clients, however, have not kept up with the evolution and as a result have limited task management features available. On the other hand, while issue tracking systems offer useful task management functionality, they are not as widespread as emails and also have a few drawbacks. This thesis reports on the exploration of the integration of the ubiquitous nature of email with the task management features of issue-tracking systems. We explore this using simple ad-hoc as well as semi-automated tasks. With these two working together, tasks can be delegated from email clients without needing to switch between the two environments. It brings some of the benefits of issue tracking systems closer to our email users.The system is developed using Microsoft VisuaI Studio.NET. with the code written in C#. The eXtreme Programming (XP) methodology was used during the development of the proof-of-concept prototype that demonstrates the integration of the two environments, as we were faced at first with vague requirements bound to change, as we better understood the problem domain through our development. XP allowed us to skip an extended and comprehensive initial design process and incrementally develop the system, making refinements and extensions as we encountered the need for them. This alleviated the need to make upfront decisions that were based on minimal knowledge of what to expect during development. This thesis describes the implementation of the prototype and the decisions made with each step taken towards developing an email-based issue tracking system. With the two environments working together, we can now easily track issues from our email clients without needing to switch to another system. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 2006
Novel approaches to the monitoring of computer networks
- Authors: Halse, G A
- Date: 2003
- Subjects: Computer networks , Computer networks -- Management , Computer networks -- South Africa -- Grahamstown , Rhodes University -- Information Technology Division
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4645 , http://hdl.handle.net/10962/d1006601
- Description: Traditional network monitoring techniques suffer from a number of limitations. They are usually designed to solve the most general case, and as a result often fall short of expectation. This project sets out to provide the network administrator with a set of alternative tools to solve specific, but common, problems. It uses the network at Rhodes University as a case study and addresses a number of issues that arise on this network. Four problematic areas are identified within this network: the automatic determination of network topology and layout, the tracking of network growth, the determination of the physical and logical locations of hosts on the network, and the need for intelligent fault reporting systems. These areas are chosen because other network monitoring techniques have failed to adequately address these problems, and because they present problems that are common across a large number of networks. Each area is examined separately and a solution is sought for each of the problems identified. As a result, a set of tools is developed to solve these problems using a number of novel network monitoring techniques. These tools are designed to be as portable as possible so as not to limit their use to the case study network. Their use within Rhodes, as well as their applicability to other situations is discussed. In all cases, any limitations and shortfalls in the approaches that were employed are examined.
- Full Text:
- Date Issued: 2003
- Authors: Halse, G A
- Date: 2003
- Subjects: Computer networks , Computer networks -- Management , Computer networks -- South Africa -- Grahamstown , Rhodes University -- Information Technology Division
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4645 , http://hdl.handle.net/10962/d1006601
- Description: Traditional network monitoring techniques suffer from a number of limitations. They are usually designed to solve the most general case, and as a result often fall short of expectation. This project sets out to provide the network administrator with a set of alternative tools to solve specific, but common, problems. It uses the network at Rhodes University as a case study and addresses a number of issues that arise on this network. Four problematic areas are identified within this network: the automatic determination of network topology and layout, the tracking of network growth, the determination of the physical and logical locations of hosts on the network, and the need for intelligent fault reporting systems. These areas are chosen because other network monitoring techniques have failed to adequately address these problems, and because they present problems that are common across a large number of networks. Each area is examined separately and a solution is sought for each of the problems identified. As a result, a set of tools is developed to solve these problems using a number of novel network monitoring techniques. These tools are designed to be as portable as possible so as not to limit their use to the case study network. Their use within Rhodes, as well as their applicability to other situations is discussed. In all cases, any limitations and shortfalls in the approaches that were employed are examined.
- Full Text:
- Date Issued: 2003
Network simulation for professional audio networks
- Authors: Otten, Fred
- Date: 2015
- Subjects: Sound engineers , Ethernet (Local area network system) , Computer networks , Computer simulation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4713 , http://hdl.handle.net/10962/d1017935
- Description: Audio Engineers are required to design and deploy large multi-channel sound systems which meet a set of requirements and use networking technologies such as Firewire and Ethernet AVB. Bandwidth utilisation and parameter groupings are among the factors which need to be considered in these designs. An implementation of an extensible, generic simulation framework would allow audio engineers to easily compare protocols and networking technologies and get near real time responses with regards to bandwidth utilisation. Our hypothesis is that an application-level capability can be developed which uses a network simulation framework to enable this process and enhances the audio engineer’s experience of designing and configuring a network. This thesis presents a new, extensible simulation framework which can be utilised to simulate professional audio networks. This framework is utilised to develop an application - AudioNetSim - based on the requirements of an audio engineer. The thesis describes the AudioNetSim models and implementations for Ethernet AVB, Firewire and the AES- 64 control protocol. AudioNetSim enables bandwidth usage determination for any network configuration and connection scenario and is used to compare Firewire and Ethernet AVB bandwidth utilisation. It also applies graph theory to the circular join problem and provides a solution to detect circular joins.
- Full Text:
- Date Issued: 2015
- Authors: Otten, Fred
- Date: 2015
- Subjects: Sound engineers , Ethernet (Local area network system) , Computer networks , Computer simulation
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4713 , http://hdl.handle.net/10962/d1017935
- Description: Audio Engineers are required to design and deploy large multi-channel sound systems which meet a set of requirements and use networking technologies such as Firewire and Ethernet AVB. Bandwidth utilisation and parameter groupings are among the factors which need to be considered in these designs. An implementation of an extensible, generic simulation framework would allow audio engineers to easily compare protocols and networking technologies and get near real time responses with regards to bandwidth utilisation. Our hypothesis is that an application-level capability can be developed which uses a network simulation framework to enable this process and enhances the audio engineer’s experience of designing and configuring a network. This thesis presents a new, extensible simulation framework which can be utilised to simulate professional audio networks. This framework is utilised to develop an application - AudioNetSim - based on the requirements of an audio engineer. The thesis describes the AudioNetSim models and implementations for Ethernet AVB, Firewire and the AES- 64 control protocol. AudioNetSim enables bandwidth usage determination for any network configuration and connection scenario and is used to compare Firewire and Ethernet AVB bandwidth utilisation. It also applies graph theory to the circular join problem and provides a solution to detect circular joins.
- Full Text:
- Date Issued: 2015
An investigation into the design and implementation of an internet-scale network simulator
- Authors: Richter, John Peter Frank
- Date: 2009
- Subjects: Computer simulation , Computer network resources , Computer networks , Internet
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4597 , http://hdl.handle.net/10962/d1004840 , Computer simulation , Computer network resources , Computer networks , Internet
- Description: Simulation is a complex task with many research applications - chiey as a research tool, to test and evaluate hypothetical scenarios. Though many simulations execute similar operations and utilise similar data, there are few simulation frameworks or toolkits that allow researchers to rapidly develop their concepts. Those that are available to researchers are limited in scope, or use old technology that is no longer useful to modern researchers. As a result of this, many researchers build their own simulations without a framework, wasting time and resources on a system that could already cater for the majority of their simulation's requirements. In this work, a system is proposed for the creation of a scalable, dynamic-resolution network simulation framework that provides scalable scope for researchers, using modern technologies and languages. This framework should allow researchers to rapidly develop a broad range of semantically-rich simulations, without the necessity of superor grid-computers or clusters. Design and implementation are discussed and alternative network simulations are compared to the proposed framework. A series of simulations, focusing on malware, is run on an implementation of this framework, and the results are compared to expectations for the outcomes of those simulations. In conclusion, a critical review of the simulator is made, considering any extensions or shortcomings that need to be addressed.
- Full Text:
- Date Issued: 2009
- Authors: Richter, John Peter Frank
- Date: 2009
- Subjects: Computer simulation , Computer network resources , Computer networks , Internet
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4597 , http://hdl.handle.net/10962/d1004840 , Computer simulation , Computer network resources , Computer networks , Internet
- Description: Simulation is a complex task with many research applications - chiey as a research tool, to test and evaluate hypothetical scenarios. Though many simulations execute similar operations and utilise similar data, there are few simulation frameworks or toolkits that allow researchers to rapidly develop their concepts. Those that are available to researchers are limited in scope, or use old technology that is no longer useful to modern researchers. As a result of this, many researchers build their own simulations without a framework, wasting time and resources on a system that could already cater for the majority of their simulation's requirements. In this work, a system is proposed for the creation of a scalable, dynamic-resolution network simulation framework that provides scalable scope for researchers, using modern technologies and languages. This framework should allow researchers to rapidly develop a broad range of semantically-rich simulations, without the necessity of superor grid-computers or clusters. Design and implementation are discussed and alternative network simulations are compared to the proposed framework. A series of simulations, focusing on malware, is run on an implementation of this framework, and the results are compared to expectations for the outcomes of those simulations. In conclusion, a critical review of the simulator is made, considering any extensions or shortcomings that need to be addressed.
- Full Text:
- Date Issued: 2009
Topic map for representing network security competencies
- Authors: Yekela, Odwa
- Date: 2018
- Subjects: Computer networks , Computer networks -- Security measures Computers -- Access control
- Language: English
- Type: Thesis , Masters , MIT
- Identifier: http://hdl.handle.net/10948/36368 , vital:33931
- Description: Competencies represent the knowledge, skills and attitudes required for job roles. Organisations need to understand and grow competencies within their workforce in order to be more competitive and to maximise new market opportunities. Competency Management is the process of introducing, managing and enforcing competencies in organisations. Through this process, occupational competencies can be assessed to see if candidates match the required job role expectations. The assessment of competencies can be conceptualised from two perspectives. The rst is `competency frameworks', which describe competencies from a high-level overview. As such, they are regarded as theWhat" element of competency. The second perspective is `competencybased learning', which focuses on addressing competencies from a more detailed, task-oriented perspective. Competency-based learning is regarded as the How" element of competency. Currently, there is no available tool that can map the What" with the How" element of competency. Such a mapping would provide a more holistic approach to representing competencies. This dissertation adopts the topic map standard in order to demonstrate a holistic approach to mapping competencies, specially in network security. This is accomplished through the design and evaluation of a Design Science artefact. In this research process a topic map data model was constructed from mapping the `What' and `How' elements together. To demonstrate the applicability of the model, it was implemented in a Computer Security Incident Response Team (CSIRT) recruitment scenario. The aim of this demonstration was to prove that the topic map could be implemented in an organisational context.
- Full Text:
- Date Issued: 2018
- Authors: Yekela, Odwa
- Date: 2018
- Subjects: Computer networks , Computer networks -- Security measures Computers -- Access control
- Language: English
- Type: Thesis , Masters , MIT
- Identifier: http://hdl.handle.net/10948/36368 , vital:33931
- Description: Competencies represent the knowledge, skills and attitudes required for job roles. Organisations need to understand and grow competencies within their workforce in order to be more competitive and to maximise new market opportunities. Competency Management is the process of introducing, managing and enforcing competencies in organisations. Through this process, occupational competencies can be assessed to see if candidates match the required job role expectations. The assessment of competencies can be conceptualised from two perspectives. The rst is `competency frameworks', which describe competencies from a high-level overview. As such, they are regarded as theWhat" element of competency. The second perspective is `competencybased learning', which focuses on addressing competencies from a more detailed, task-oriented perspective. Competency-based learning is regarded as the How" element of competency. Currently, there is no available tool that can map the What" with the How" element of competency. Such a mapping would provide a more holistic approach to representing competencies. This dissertation adopts the topic map standard in order to demonstrate a holistic approach to mapping competencies, specially in network security. This is accomplished through the design and evaluation of a Design Science artefact. In this research process a topic map data model was constructed from mapping the `What' and `How' elements together. To demonstrate the applicability of the model, it was implemented in a Computer Security Incident Response Team (CSIRT) recruitment scenario. The aim of this demonstration was to prove that the topic map could be implemented in an organisational context.
- Full Text:
- Date Issued: 2018
Investigating call control using MGCP in conjuction with SIP and H.323
- Authors: Jacobs, Ashley
- Date: 2005 , 2005-03-14
- Subjects: Communication -- Technological innovations , Digital telephone systems , Computer networks , Computer network protocols , Internet telephony
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4631 , http://hdl.handle.net/10962/d1006516 , Communication -- Technological innovations , Digital telephone systems , Computer networks , Computer network protocols , Internet telephony
- Description: Telephony used to mean using a telephone to call another telephone on the Public Switched Telephone Network (PSTN), and data networks were used purely to allow computers to communicate. However, with the advent of the Internet, telephony services have been extended to run on data networks. Telephone calls within the IP network are known as Voice over IP. These calls are carried by a number of protocols, with the most popular ones currently being Session Initiation Protocol (SIP) and H.323. Calls can be made from the IP network to the PSTN and vice versa through the use of a gateway. The gateway translates the packets from the IP network to circuits on the PSTN and vice versa to facilitate calls between the two networks. Gateways have evolved and are now split into two entities using the master/slave architecture. The master is an intelligent Media Gateway Controller (MGC) that handles the call control and signalling. The slave is a "dumb" Media Gateway (MG) that handles the translation of the media. The current gateway control protocols in use are Megaco/H.248, MGCP and Skinny. These protocols have proved themselves on the edge of the network. Furthermore, since they communicate with the call signalling VoIP protocols as well as the PSTN, they have to be the lingua franca between the two networks. Within the VoIP network, the numbers of call signalling protocols make it difficult to communicate with each other and to create services. This research investigates the use of Gateway Control Protocols as the lowest common denominator between the call signalling protocols SIP and H.323. More specifically, it uses MGCP to investigate service creation. It also considers the use of MGCP as a protocol translator between SIP and H.323. A service was created using MGCP to allow H.323 endpoints to send Short Message Service (SMS) messages. This service was then extended with minimal effort to SIP endpoints. This service investigated MGCP’s ability to handle call control from the H.323 and SIP endpoints. An MGC was then successfully used to perform as a protocol translator between SIP and H.323.
- Full Text:
- Date Issued: 2005
- Authors: Jacobs, Ashley
- Date: 2005 , 2005-03-14
- Subjects: Communication -- Technological innovations , Digital telephone systems , Computer networks , Computer network protocols , Internet telephony
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4631 , http://hdl.handle.net/10962/d1006516 , Communication -- Technological innovations , Digital telephone systems , Computer networks , Computer network protocols , Internet telephony
- Description: Telephony used to mean using a telephone to call another telephone on the Public Switched Telephone Network (PSTN), and data networks were used purely to allow computers to communicate. However, with the advent of the Internet, telephony services have been extended to run on data networks. Telephone calls within the IP network are known as Voice over IP. These calls are carried by a number of protocols, with the most popular ones currently being Session Initiation Protocol (SIP) and H.323. Calls can be made from the IP network to the PSTN and vice versa through the use of a gateway. The gateway translates the packets from the IP network to circuits on the PSTN and vice versa to facilitate calls between the two networks. Gateways have evolved and are now split into two entities using the master/slave architecture. The master is an intelligent Media Gateway Controller (MGC) that handles the call control and signalling. The slave is a "dumb" Media Gateway (MG) that handles the translation of the media. The current gateway control protocols in use are Megaco/H.248, MGCP and Skinny. These protocols have proved themselves on the edge of the network. Furthermore, since they communicate with the call signalling VoIP protocols as well as the PSTN, they have to be the lingua franca between the two networks. Within the VoIP network, the numbers of call signalling protocols make it difficult to communicate with each other and to create services. This research investigates the use of Gateway Control Protocols as the lowest common denominator between the call signalling protocols SIP and H.323. More specifically, it uses MGCP to investigate service creation. It also considers the use of MGCP as a protocol translator between SIP and H.323. A service was created using MGCP to allow H.323 endpoints to send Short Message Service (SMS) messages. This service was then extended with minimal effort to SIP endpoints. This service investigated MGCP’s ability to handle call control from the H.323 and SIP endpoints. An MGC was then successfully used to perform as a protocol translator between SIP and H.323.
- Full Text:
- Date Issued: 2005
A framework for responsive content adaptation in electronic display networks
- Authors: West, Philip
- Date: 2006
- Subjects: Computer networks , Cell phone systems , Wireless communication systems , Mobile communication systems , HTML (Document markup language) , XML (Document markup language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4589 , http://hdl.handle.net/10962/d1004824 , Computer networks , Cell phone systems , Wireless communication systems , Mobile communication systems , HTML (Document markup language) , XML (Document markup language)
- Description: Recent trends show an increase in the availability and functionality of handheld devices, wireless network technology, and electronic display networks. We propose the novel integration of these technologies to provide wireless access to content delivered to large-screen display systems. Content adaptation is used as a method of reformatting web pages to display more appropriately on handheld devices, and to remove unwanted content. A framework is presented that facilitates content adaptation, implemented as an adaptation layer, which is extended to provide personalization of adaptation settings and response to network conditions. The framework is implemented as a proxy server for a wireless network, and handles HTML and XML documents. Once a document has been requested by a user, the HTML/XML is retrieved and parsed, creating a Document Object Model tree representation. It is then altered according to the user’s personal settings or predefined settings, based on current network usage and the network resources available. Three adaptation techniques were implemented; spatial representation, which generates an image map of the document, text summarization, which creates a tree view representation of a document, and tag extraction, which replaces specific tags with links. Three proof-of-concept systems were developed in order to test the robustness of the framework. A system for use with digital slide shows, a digital signage system, and a generalized system for use with the internet were implemented. Testing was performed by accessing sample web pages through the content adaptation proxy server. Tag extraction works correctly for all HTML and XML document structures, whereas spatial representation and text summarization are limited to a controlled subset. Results indicate that the adaptive system has the ability to reduce average bandwidth usage, by decreasing the amount of data on the network, thereby allowing a greater number of users access to content. This suggests that responsive content adaptation has a positive influence on network performance metrics.
- Full Text:
- Date Issued: 2006
- Authors: West, Philip
- Date: 2006
- Subjects: Computer networks , Cell phone systems , Wireless communication systems , Mobile communication systems , HTML (Document markup language) , XML (Document markup language)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4589 , http://hdl.handle.net/10962/d1004824 , Computer networks , Cell phone systems , Wireless communication systems , Mobile communication systems , HTML (Document markup language) , XML (Document markup language)
- Description: Recent trends show an increase in the availability and functionality of handheld devices, wireless network technology, and electronic display networks. We propose the novel integration of these technologies to provide wireless access to content delivered to large-screen display systems. Content adaptation is used as a method of reformatting web pages to display more appropriately on handheld devices, and to remove unwanted content. A framework is presented that facilitates content adaptation, implemented as an adaptation layer, which is extended to provide personalization of adaptation settings and response to network conditions. The framework is implemented as a proxy server for a wireless network, and handles HTML and XML documents. Once a document has been requested by a user, the HTML/XML is retrieved and parsed, creating a Document Object Model tree representation. It is then altered according to the user’s personal settings or predefined settings, based on current network usage and the network resources available. Three adaptation techniques were implemented; spatial representation, which generates an image map of the document, text summarization, which creates a tree view representation of a document, and tag extraction, which replaces specific tags with links. Three proof-of-concept systems were developed in order to test the robustness of the framework. A system for use with digital slide shows, a digital signage system, and a generalized system for use with the internet were implemented. Testing was performed by accessing sample web pages through the content adaptation proxy server. Tag extraction works correctly for all HTML and XML document structures, whereas spatial representation and text summarization are limited to a controlled subset. Results indicate that the adaptive system has the ability to reduce average bandwidth usage, by decreasing the amount of data on the network, thereby allowing a greater number of users access to content. This suggests that responsive content adaptation has a positive influence on network performance metrics.
- Full Text:
- Date Issued: 2006
Using semantic knowledge to improve compression on log files
- Authors: Otten, Frederick John
- Date: 2009 , 2008-11-19
- Subjects: Computer networks , Data compression (Computer science) , Semantics--Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4650 , http://hdl.handle.net/10962/d1006619 , Computer networks , Data compression (Computer science) , Semantics--Data processing
- Description: With the move towards global and multi-national companies, information technology infrastructure requirements are increasing. As the size of these computer networks increases, it becomes more and more difficult to monitor, control, and secure them. Networks consist of a number of diverse devices, sensors, and gateways which are often spread over large geographical areas. Each of these devices produce log files which need to be analysed and monitored to provide network security and satisfy regulations. Data compression programs such as gzip and bzip2 are commonly used to reduce the quantity of data for archival purposes after the log files have been rotated. However, there are many other compression programs which exist - each with their own advantages and disadvantages. These programs each use a different amount of memory and take different compression and decompression times to achieve different compression ratios. System log files also contain redundancy which is not necessarily exploited by standard compression programs. Log messages usually use a similar format with a defined syntax. In the log files, all the ASCII characters are not used and the messages contain certain "phrases" which often repeated. This thesis investigates the use of compression as a means of data reduction and how the use of semantic knowledge can improve data compression (also applying results to different scenarios that can occur in a distributed computing environment). It presents the results of a series of tests performed on different log files. It also examines the semantic knowledge which exists in maillog files and how it can be exploited to improve the compression results. The results from a series of text preprocessors which exploit this knowledge are presented and evaluated. These preprocessors include: one which replaces the timestamps and IP addresses with their binary equivalents and one which replaces words from a dictionary with unused ASCII characters. In this thesis, data compression is shown to be an effective method of data reduction producing up to 98 percent reduction in filesize on a corpus of log files. The use of preprocessors which exploit semantic knowledge results in up to 56 percent improvement in overall compression time and up to 32 percent reduction in compressed size. , TeX , pdfTeX-1.40.3
- Full Text:
- Date Issued: 2009
- Authors: Otten, Frederick John
- Date: 2009 , 2008-11-19
- Subjects: Computer networks , Data compression (Computer science) , Semantics--Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4650 , http://hdl.handle.net/10962/d1006619 , Computer networks , Data compression (Computer science) , Semantics--Data processing
- Description: With the move towards global and multi-national companies, information technology infrastructure requirements are increasing. As the size of these computer networks increases, it becomes more and more difficult to monitor, control, and secure them. Networks consist of a number of diverse devices, sensors, and gateways which are often spread over large geographical areas. Each of these devices produce log files which need to be analysed and monitored to provide network security and satisfy regulations. Data compression programs such as gzip and bzip2 are commonly used to reduce the quantity of data for archival purposes after the log files have been rotated. However, there are many other compression programs which exist - each with their own advantages and disadvantages. These programs each use a different amount of memory and take different compression and decompression times to achieve different compression ratios. System log files also contain redundancy which is not necessarily exploited by standard compression programs. Log messages usually use a similar format with a defined syntax. In the log files, all the ASCII characters are not used and the messages contain certain "phrases" which often repeated. This thesis investigates the use of compression as a means of data reduction and how the use of semantic knowledge can improve data compression (also applying results to different scenarios that can occur in a distributed computing environment). It presents the results of a series of tests performed on different log files. It also examines the semantic knowledge which exists in maillog files and how it can be exploited to improve the compression results. The results from a series of text preprocessors which exploit this knowledge are presented and evaluated. These preprocessors include: one which replaces the timestamps and IP addresses with their binary equivalents and one which replaces words from a dictionary with unused ASCII characters. In this thesis, data compression is shown to be an effective method of data reduction producing up to 98 percent reduction in filesize on a corpus of log files. The use of preprocessors which exploit semantic knowledge results in up to 56 percent improvement in overall compression time and up to 32 percent reduction in compressed size. , TeX , pdfTeX-1.40.3
- Full Text:
- Date Issued: 2009
A framework for secure mobility in wireless overlay networks
- Authors: Chen, Hejun
- Date: 2006
- Subjects: Wireless communication systems , Computer networks
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9778 , http://hdl.handle.net/10948/819 , Wireless communication systems , Computer networks
- Description: Various wireless networks are widely deployed world wide. Current technologies employed in these networks vary widely in terms of bandwidths, latencies, frequencies, and media access methods. Most existing wireless network technologies can be divided into two categories: those that provide a low-bandwidth service over a wide geographic area, for example UMTS, and those that provide a high bandwidth service over a narrow geographic area, for example 802.11. Although it would be desirable to provide a high- bandwidth service over a wide coverage region to mobile users all the time, no single wireless network technology simultaneously satisfies these require- ments. Wireless Overlay Networks, a hierarchical structure of wireless personal area, local area, and wide area data networks, is considered as an efficient and scalable way to solve this problem. Due to the wide deployment of UMTS and 802.11 WLAN, this study attempts to combine them to implement the concept of Wireless Overlay Net- works. Furthermore, the information transmitted over this Wireless Overlay Networks is protected in terms of authentication, integrity and confidentiality. To achieve this goal, this study aims to combine GPRS, Mobile IP and IPSec to propose a framework for secure mobility in Wireless Overlay Networks. The framework is developed in three steps: Firstly, this study addresses the problem of combining GPRS and Mo- bile IP, so that GPRS users are provided with Mobile IP service. This results in presenting a uniform Mobile IP interface to peers regardless of whether mobile users use UMTS or 802.11 WLAN. Secondly, this study discovers the existing problem when combining Mobile IP and IPSec, and proposes a Dual Home Agent Architecture to achieve secure mobility. Finally, based on the output of the previous two steps, a complete framework is proposed, which achieves secure mobility in Wireless Overlay Networks, specifically, in UMTS and 802.11 WLAN. The framework also implements seamless handover when mobile users switch between UMTS and 802.11. This results in UMTS and 802.11 WLAN looking like a single network when participating in this framework, and presents seamless and secure mobility.
- Full Text:
- Date Issued: 2006
- Authors: Chen, Hejun
- Date: 2006
- Subjects: Wireless communication systems , Computer networks
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9778 , http://hdl.handle.net/10948/819 , Wireless communication systems , Computer networks
- Description: Various wireless networks are widely deployed world wide. Current technologies employed in these networks vary widely in terms of bandwidths, latencies, frequencies, and media access methods. Most existing wireless network technologies can be divided into two categories: those that provide a low-bandwidth service over a wide geographic area, for example UMTS, and those that provide a high bandwidth service over a narrow geographic area, for example 802.11. Although it would be desirable to provide a high- bandwidth service over a wide coverage region to mobile users all the time, no single wireless network technology simultaneously satisfies these require- ments. Wireless Overlay Networks, a hierarchical structure of wireless personal area, local area, and wide area data networks, is considered as an efficient and scalable way to solve this problem. Due to the wide deployment of UMTS and 802.11 WLAN, this study attempts to combine them to implement the concept of Wireless Overlay Net- works. Furthermore, the information transmitted over this Wireless Overlay Networks is protected in terms of authentication, integrity and confidentiality. To achieve this goal, this study aims to combine GPRS, Mobile IP and IPSec to propose a framework for secure mobility in Wireless Overlay Networks. The framework is developed in three steps: Firstly, this study addresses the problem of combining GPRS and Mo- bile IP, so that GPRS users are provided with Mobile IP service. This results in presenting a uniform Mobile IP interface to peers regardless of whether mobile users use UMTS or 802.11 WLAN. Secondly, this study discovers the existing problem when combining Mobile IP and IPSec, and proposes a Dual Home Agent Architecture to achieve secure mobility. Finally, based on the output of the previous two steps, a complete framework is proposed, which achieves secure mobility in Wireless Overlay Networks, specifically, in UMTS and 802.11 WLAN. The framework also implements seamless handover when mobile users switch between UMTS and 802.11. This results in UMTS and 802.11 WLAN looking like a single network when participating in this framework, and presents seamless and secure mobility.
- Full Text:
- Date Issued: 2006
A P2P middleware design for digital access nodes in marginalised rural areas
- Authors: Wertlen, Ronald
- Date: 2010
- Subjects: Software design , Rural development -- South Africa -- Eastern Cape , Rural development projects -- South Africa -- Eastern Cape , Sustainable development -- Simulation methods , Computer networks , Data transmission systems , Electronic data processing -- Distributed processing , Middleware -- Development , Computer software
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: vital:11391 , http://hdl.handle.net/10353/254 , Software design , Rural development -- South Africa -- Eastern Cape , Rural development projects -- South Africa -- Eastern Cape , Sustainable development -- Simulation methods , Computer networks , Data transmission systems , Electronic data processing -- Distributed processing , Middleware -- Development , Computer software
- Description: This thesis addresses software design within the field of Information and Communications Technology for Development (ICTD). Specifically, it makes a case for the design and development of software which is custom-made for the context of marginalised rural areas (MRAs). One of the main aims of any ICTD project is sustainability and such sustainability is particularly difficult in MRAs because of the high costs of projects located there. Most literature on ICTD projects focuses on other factors, such as management, regulations, social and community issues when discussing this issue. Technical matters are often down-played or ignored entirely. This thesis argues that MRAs exhibit unique technical characteristics and that by understanding these characteristics, one can possibly design more cost-effective software. One specific characteristic is described and addressed in this thesis – a characteristic we describe here for the first time and call a network island. Further analysis of the literature generates a picture of a distributed network of access nodes (DANs) within such network islands, which are connected by high speed networks and are able to share resources and stimulate usage of technology by offering a wide range of services. This thesis attempts to design a fitting middleware platform for such a context, which would achieve the following aims: i) allow software developers to create solutions for the context more efficiently (correctly, rapidly); ii) stimulate product managers and business owners to create innovative software products more easily (cost-effectively). A given in the context of this thesis is that the software should use free/libre open source software (FLOSS) – good arguments do also exist for the use of FLOSS. A review of useful FLOSS frameworks is undertaken and several of these are examined in an applied part of the thesis, to see how useful they may be. They form the basis for a walking skeleton implementation of the proposed middleware. The Spring framework is the basis for experiments, along with Spring-Webservices, JMX and PHP 5’s web service capabilities. This thesis builds on three years of work at the Siyakhula Living Lab (SLL), an experimental testbed in a MRA in the Mbashe district of the Eastern Cape of South Africa. Several existing products are deployed at the SLL in the fields of eCommerce, eGovernment and eLearning. Requirements specifications are engineered from a variety of sources, including interviews, mailing lists, the author’s experience as a supervisor at the SLL, and a review of the existing SLL products. Future products are also investigated, as the thesis considers current trends in ICTD. Use cases are also derived and listed. Most of the use cases are concerned with management functions of DANs that can be automated, so that operators of DANs can focus on their core business and not on technology. Using the UML Components methodology, the thesis then proceeds to design a middleware component architecture that is derived from the requirements specification. The process proceeds step-by-step, so that the reader can follow how business rules, operations and interfaces are derived from the use cases. Ultimately, the business rules, interfaces and operations are related to business logic, system interfaces and operations that are situated in specific components. The components in turn are derived from the business information model, that is derived from the business concepts that were initially used to describe the context for the requirements engineering. In this way, a logical method for software design is applied to the problem domain to methodically derive a software design for a middleware solution. The thesis tests the design by considering possible weaknesses in the design. The network aspect is tested by interpolating from formal assumptions about the nature of the context. The data access layer is also identified as a possible bottleneck. We suggest the use of fast indexing methods instead of relational databases to maintain flexibility and efficiency of the data layer. Lessons learned from the exercise are discussed, within the context of the author’s experience in software development teams, as well as in ICTD projects. This synthesis of information leads to warnings about the psychology of middleware development. We note that the ICTD domain is a particularly difficult one with regards to software development as business requirements are not usually clearly formulated and developers do not have the requisite domain knowledge. In conclusion, the core arguments of the thesis are recounted in a bullet form, to lay bare the reasoning behind this work. Novel aspects of the work are also highlighted. They include the description of a network island, and aspects of the DAN middleware requirements engineering and design. Future steps for work based on this thesis are mapped out and open problems relating to this research are touched upon.
- Full Text:
- Date Issued: 2010
- Authors: Wertlen, Ronald
- Date: 2010
- Subjects: Software design , Rural development -- South Africa -- Eastern Cape , Rural development projects -- South Africa -- Eastern Cape , Sustainable development -- Simulation methods , Computer networks , Data transmission systems , Electronic data processing -- Distributed processing , Middleware -- Development , Computer software
- Language: English
- Type: Thesis , Masters , MSc (Computer Science)
- Identifier: vital:11391 , http://hdl.handle.net/10353/254 , Software design , Rural development -- South Africa -- Eastern Cape , Rural development projects -- South Africa -- Eastern Cape , Sustainable development -- Simulation methods , Computer networks , Data transmission systems , Electronic data processing -- Distributed processing , Middleware -- Development , Computer software
- Description: This thesis addresses software design within the field of Information and Communications Technology for Development (ICTD). Specifically, it makes a case for the design and development of software which is custom-made for the context of marginalised rural areas (MRAs). One of the main aims of any ICTD project is sustainability and such sustainability is particularly difficult in MRAs because of the high costs of projects located there. Most literature on ICTD projects focuses on other factors, such as management, regulations, social and community issues when discussing this issue. Technical matters are often down-played or ignored entirely. This thesis argues that MRAs exhibit unique technical characteristics and that by understanding these characteristics, one can possibly design more cost-effective software. One specific characteristic is described and addressed in this thesis – a characteristic we describe here for the first time and call a network island. Further analysis of the literature generates a picture of a distributed network of access nodes (DANs) within such network islands, which are connected by high speed networks and are able to share resources and stimulate usage of technology by offering a wide range of services. This thesis attempts to design a fitting middleware platform for such a context, which would achieve the following aims: i) allow software developers to create solutions for the context more efficiently (correctly, rapidly); ii) stimulate product managers and business owners to create innovative software products more easily (cost-effectively). A given in the context of this thesis is that the software should use free/libre open source software (FLOSS) – good arguments do also exist for the use of FLOSS. A review of useful FLOSS frameworks is undertaken and several of these are examined in an applied part of the thesis, to see how useful they may be. They form the basis for a walking skeleton implementation of the proposed middleware. The Spring framework is the basis for experiments, along with Spring-Webservices, JMX and PHP 5’s web service capabilities. This thesis builds on three years of work at the Siyakhula Living Lab (SLL), an experimental testbed in a MRA in the Mbashe district of the Eastern Cape of South Africa. Several existing products are deployed at the SLL in the fields of eCommerce, eGovernment and eLearning. Requirements specifications are engineered from a variety of sources, including interviews, mailing lists, the author’s experience as a supervisor at the SLL, and a review of the existing SLL products. Future products are also investigated, as the thesis considers current trends in ICTD. Use cases are also derived and listed. Most of the use cases are concerned with management functions of DANs that can be automated, so that operators of DANs can focus on their core business and not on technology. Using the UML Components methodology, the thesis then proceeds to design a middleware component architecture that is derived from the requirements specification. The process proceeds step-by-step, so that the reader can follow how business rules, operations and interfaces are derived from the use cases. Ultimately, the business rules, interfaces and operations are related to business logic, system interfaces and operations that are situated in specific components. The components in turn are derived from the business information model, that is derived from the business concepts that were initially used to describe the context for the requirements engineering. In this way, a logical method for software design is applied to the problem domain to methodically derive a software design for a middleware solution. The thesis tests the design by considering possible weaknesses in the design. The network aspect is tested by interpolating from formal assumptions about the nature of the context. The data access layer is also identified as a possible bottleneck. We suggest the use of fast indexing methods instead of relational databases to maintain flexibility and efficiency of the data layer. Lessons learned from the exercise are discussed, within the context of the author’s experience in software development teams, as well as in ICTD projects. This synthesis of information leads to warnings about the psychology of middleware development. We note that the ICTD domain is a particularly difficult one with regards to software development as business requirements are not usually clearly formulated and developers do not have the requisite domain knowledge. In conclusion, the core arguments of the thesis are recounted in a bullet form, to lay bare the reasoning behind this work. Novel aspects of the work are also highlighted. They include the description of a network island, and aspects of the DAN middleware requirements engineering and design. Future steps for work based on this thesis are mapped out and open problems relating to this research are touched upon.
- Full Text:
- Date Issued: 2010
Routing MIDI messages in a shared music studio environment
- Authors: Mosala, Thabo Jerry
- Date: 1995
- Subjects: MIDI (Standard) , Computer networks
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4672 , http://hdl.handle.net/10962/d1006695 , MIDI (Standard) , Computer networks
- Description: The Rhodes Computer Music Network (RHOCMN) is a network which allows main studio resources to be shared. RHOCMN is growing into a multi-workstation environment and additional devices are being incorporated into the system. A star configuration is used for transmitting MIDI from a MIDI patch bay to the workstations and MIDI devices. This imposes several disadvantages on the use of the studio, such as wiring problems. In a quest to avoid problems related to MIDI in RHOCMN, the MIDINet system was developed. The idea was to acquire a viable solution to MIDI's main problems which does not involve a redefinition of the MIDI specification.
- Full Text:
- Date Issued: 1995
- Authors: Mosala, Thabo Jerry
- Date: 1995
- Subjects: MIDI (Standard) , Computer networks
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4672 , http://hdl.handle.net/10962/d1006695 , MIDI (Standard) , Computer networks
- Description: The Rhodes Computer Music Network (RHOCMN) is a network which allows main studio resources to be shared. RHOCMN is growing into a multi-workstation environment and additional devices are being incorporated into the system. A star configuration is used for transmitting MIDI from a MIDI patch bay to the workstations and MIDI devices. This imposes several disadvantages on the use of the studio, such as wiring problems. In a quest to avoid problems related to MIDI in RHOCMN, the MIDINet system was developed. The idea was to acquire a viable solution to MIDI's main problems which does not involve a redefinition of the MIDI specification.
- Full Text:
- Date Issued: 1995
Remora : implementing adaptive parallelism on a heterogeneous cluster of networked workstations
- Authors: Rehmet, Geoffrey Michael
- Date: 1995
- Subjects: LINDA (Computer system) , Local area networks (Computer networks) , Computer networks , Remora (Computer system)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4673 , http://hdl.handle.net/10962/d1006696 , LINDA (Computer system) , Local area networks (Computer networks) , Computer networks , Remora (Computer system)
- Description: Computers connected to a local area network are often only fully utilized for short periods of time. In fact, most workstations are not used at all for a significant portion of the day. The combined "idle time" of the workstations on a network constitutes a significant computing resource, which is generally wasted. If harnessed properly, such a resource could constitute a cheap alternative to expensive high-performance computers. Adaptive parallelism refers to the parallel execution of a computation on a dynamically changing set of processors. This thesis investigates the viability of this approach as a vehicle to harness the "idle cycles" available on a heterogeneous cluster of networked computers. A system, called Remora, which implements adaptive parallelism via the Linda programming paradigm, is presented. Experiments, performed using Remora, show that adaptive parallelism provides an efficient vehicle for using idle processor cycles, without having an adverse effect on the tasks which constitute the normal workload of the computers being used.
- Full Text:
- Date Issued: 1995
- Authors: Rehmet, Geoffrey Michael
- Date: 1995
- Subjects: LINDA (Computer system) , Local area networks (Computer networks) , Computer networks , Remora (Computer system)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4673 , http://hdl.handle.net/10962/d1006696 , LINDA (Computer system) , Local area networks (Computer networks) , Computer networks , Remora (Computer system)
- Description: Computers connected to a local area network are often only fully utilized for short periods of time. In fact, most workstations are not used at all for a significant portion of the day. The combined "idle time" of the workstations on a network constitutes a significant computing resource, which is generally wasted. If harnessed properly, such a resource could constitute a cheap alternative to expensive high-performance computers. Adaptive parallelism refers to the parallel execution of a computation on a dynamically changing set of processors. This thesis investigates the viability of this approach as a vehicle to harness the "idle cycles" available on a heterogeneous cluster of networked computers. A system, called Remora, which implements adaptive parallelism via the Linda programming paradigm, is presented. Experiments, performed using Remora, show that adaptive parallelism provides an efficient vehicle for using idle processor cycles, without having an adverse effect on the tasks which constitute the normal workload of the computers being used.
- Full Text:
- Date Issued: 1995