Finding an optimal solution to the problem of fast and efficient provisioning of reliable connections and failure recovery in future intelligent optical networks is an ongoing challenge. In this dissertation, we investigate and compare the performance of an adapted shared-path protection algorithm with a more conventional approach; both designed for survivable optical Wavelength Division Multiplexing (WDM) mesh networks. The effect of different classes of service on performance is also investigated. Dedicated path protection is a proactive scheme which reserves spare resources to combat single link failures. Conventional Shared-path Protection (CSP) is desirable due to the efficient utilization of resources which results from the sharing of backup paths. Availability is an important performance assessment factor which measures the probability that a connection is in an operational state at some point in time. It is the instantaneous counterpart of reliability. Therefore, connections that do not meet their availability requirements are considered to be unreliable. Reliability Aware Shared-path Protection (RASP) adopts the advantages of CSP by provisioning reliable connections efficiently, but provides protection for unreliable connections only. With the use of a link disjoint parameter, RASP also permits the routing of partial link disjoint backup paths. A simulation study, which evaluates four performance parameters, is undertaken using a South African mesh network. The parameters that are investigated are: 1. Blocking Probability (BP), which considers the percentage of connection requests that are blocked, 2. Backup Success Ratio (BSR), which considers the number of connections that are successfully provisioned with a backup protection path, 3. Backup Primary Resource Ratio (BPR), which considers the ratio of resources utilized to cater for working traffic to the resources reserved for protection paths and lastly 4. Reliability Satisfaction Ratio (RSR), which evaluates the ratio of provisioned connections that meet their availability requirements to the total number of provisioned connections. Under dynamic traffic conditions with varying network load, simulation results show that RASP can provision reliable connections and satisfy Service Level Agreement (SLA) requirements. A competitive Blocking Probability (BP) and lower Backup Primary Resource Ratio (BPR) signify an improvement in resource utilization efficiency. A higher Backup Success Ratio (BSR) was also achieved under high Quality of Service (QoS) constraints. The significance of different availability requirements is evaluated by creating three categories, high availability, medium availability and low availability. These three categories represent three classes of service, with availability used as the QoS parameter. Within each class, the performance of RASP and CSP is observed and analyzed, using the parameters described above. Results show that both the BP and BPR increase with an increase in the availability requirements. The RSR decreases as the reliability requirements increase and a variation in BSR is also indicated. / Dissertation (MEng)--University of Pretoria, 2009. / Electrical, Electronic and Computer Engineering / unrestricted

L'informatique en nuage (cloud computing) est un paradigme émergent qui révolutionne l'utilisation et la commercialisation des services informatiques. De nos jours, l'impact socio-économique de l'informatique en nuage et plus particulièrement des services de PaaS (plate-forme en tant que service) devient essentiel, puisque le nombre d'utilisateurs et de fournisseurs des cloud PaaS est en pleine croissance. L'objectif principal des fournisseurs de cloud PaaS est de générer le maximum de profit des services qu'ils fournissent. Cela les oblige à faire face à un certain nombre de défis, tels que la gestion efficace des ressources sous-jacentes et la satisfaction des SLAs (contrat de service) des applications hébergées. Dans cette thèse, nous considérons un environnement PaaS hybride de cloud bursting, où le fournisseur PaaS possède un nombre limité de ressources privées et a la possibilité de louer des ressources publiques. Ce choix permet au fournisseur PaaS d'avoir un contrôle complet sur les services hébergés dans les ressources privées et de profiter de ressources publiques pour gérer les périodes de pointe. De plus, nous proposons une solution rentable pour gérer un tel système PaaS sous des contraintes de SLA. Nous définissons une politique d'optimisation de profit qui, à chaque requête d'un nouveau client, évalue le coût d'hébergement de son application en utilisant les ressources publiques et privées et choisit l'option qui génère le plus de profit. Pendant les périodes de pointe la politique considère deux autres options. La première option consiste à emprunter quelques ressources aux applications en cours d'exécution tout en considérant le paiement de pénalités si leur qualité de service est affectée. La seconde option consiste à attendre que des ressources privées soient libérés tout en considérant le paiement de pénalités si la qualité de service de la nouvelle application est affectée. En outre, nous avons conçu et mis en œuvre une architecture de cloud PaaS, appelée Meryn, qui intègre la politique d'optimisation proposée, supporte le cloud bursting et héberge des applications du type batch et MapReduce. Les résultats de notre évaluation montrent l'efficacité de notre approche dans l'optimisation du profit du fournisseur. En effet, comparée à une approche de base, notre approche fournit jusqu'à 11.59 % et 9.02 % plus de profits pour le fournisseur dans respectivement les simulations et les expériences. / Cloud computing is an emerging paradigm revolutionizing the use and marketing of information technology. As the number of cloud users and providers grows, the socio-economical impact of cloud solutions and particularly PaaS (platform as a service) solutions is becoming increasingly critical. The main objective of PaaS providers is to generate the maximum profit from the services they provide. This requires them to face a number of challenges such as efficiently managing the underlying resources and satisfying the SLAs of the hosted applications. This thesis considers a cloud-bursting PaaS environment where the PaaS provider owns a limited number of private resources and is able to rent public cloud resources, when needed. This environment enables the PaaS provider to have full control over services hosted on the private cloud and to take advantage of public clouds for managing peak periods. In this context, we propose a profit-efficient solution for managing the cloud-bursting PaaS system under SLA constraints. We define a profit optimization policy that, after each client request, evaluates the cost of hosting the application using public and private resources and chooses the option that generates the highest profit. During peak periods the optimization policy considers two more options. The first option is to take some resources from running applications, taking into account the payment of penalties if their promised quality of service is affected. The second option is to wait until private resources become available, taking into account the payment of penalties if the promised quality of service of the new application is affected. Furthermore we designed and implemented an open cloud-bursting PaaS system, called Meryn, which integrates the proposed optimization policy and provides support for batch and MapReduce applications. The results of our evaluation show the effectiveness of our approach in optimizing the provider profit. Indeed, compared to a basic approach, our approach provides up to 11.59% and 9.02% more provider profit in, respectively, simulations and experiments.

IT solutions must be protected so that the business can continue, even in the case of fatal failures associated with disasters. Business continuity in the context of disaster implies that business cannot continue in the current environment but instead must continue at an alternate site or data center. However, the BC/DR concept today is too fragmented, as many different frameworks and methodologies exist. Furthermore,many of the application-specific solutions are provided and promoted by software vendors, while hardware vendors provide solutions for their hardware environments. Nevertheless, there are concerns that BC/DR solutions often do not connect to the technical components that are in the lower layers, which function as the foundationfor any such solutions; hence, it is equally important to connect and map the requirements accordingly. Moreover, a shift in the hardware environment, such as cloud computing, as well as changes in operations management, such as outsourcing,add complexity that must be captured by a BC/DR solution. Furthermore, the integrated nature of IT-based business solutions also presents new challenges, as it isno longer one IT solution that must be protected but also other IT solutions that are integrated to deliver an individual business process. Thus, it will be difficult to employa current BC/DR approach. Hence, the purpose of this thesis project is to design, develop, and present a novel way of addressing the BC/DR gaps, while supporting the requirements of a dynamic IT environment. The solution reuses most elements fromthe existing standards and solutions. However, it also includes new elements to capture and present the technical solution; hence, the complete solution is designatedas a framework. The new framework can support many IT solutions since it will havea modular approach, and it is flexible, scalable, and platform and application independent, while addressing the solution on a component level. The new framework is applied to two application scenarios at the stakeholder site, and theresults are studied and presented in this thesis.

A scheduler, as a central components of a computing site, aggregates computing resources and is responsible to distribute the incoming load (jobs) between the resources. Under such an environment, the optimum performance of the system against the service level agreement (SLA) based workloads, can be achieved by calculating the priority of SLA bound jobs using integrated heuristic. The SLA defines the service obligations and expectations to use the computational resources. The integrated heuristic is the combination of different SLA terms. It combines the SLA terms with a specific weight for each term. Theweights are computed by applying parameter sweep technique in order to obtain the best schedule for the optimum performance of the system under the workload. The sweepingof parameters on the integrated heuristic observed to be computationally expensive. The integrated heuristic becomes more expensive if no value of the computed weights result in improvement in performance with the resulting schedule. Hence, instead of obtaining optimum performance it incurs computation cost in such situations. Therefore, there is a need of detection of situations where the integrated heuristic can be exploited beneficially. For that reason, in this thesis we propose a metric based on the concept of utilization, to evaluate the SLA based parallel workloads of independent jobs to detect any impact of integrated heuristic on the workload.

The master thesis deals with the status of management control system in shared services center of analyzed company in cooperation with controlling department of the local branch office in Slovakia. Theoretical part of the theses focuses on the theoretical basis for the analytical part, concerning the theory of controlling, centers of shared services in general and the transfer of controlling activities to them. The analytical part includes the analysis of current state of the controlling activities transfer and the cooperation between local controllers and controllers in shared services center. In the final part of the thesis are proposed recommendations and suggestions for possible improvements of management control system as a subsystem of management in the company.

In my thesis, I will focus on outsourcing the way it may be applied from global perspective. I will precisely define specific types of outsourcing, it`s versatility and summarize current trends in outsourcing business. Besides outsourcing, focus has also been put on managed service known as managed ICT services. Looking into these, particular interest is given to outsourcing of printing services and managed desktop services. As a result, deep dive into current situation of a concrete company was done, listing analysis of actual printing devices and desktop devices, ending with closing summary recommending the best way to implement new solution and smart ways of financing.

This thesis explores the topic of service level agreements management according to IT Infrastructure Library as a structured document. First of all ITIL in general is briefly described, analysis and a structure of SLA is then defined. This is a base for conceptual model definition. Later design and implementation of a web service and a client web application are presented. Both applications will be used as a tool in the course being held by our faculty.

This Master’s Thesis in Electrical Engineering concerns the introduction of a Parlay gateway in Skanova’s public circuit switched telephone network, what network integrity problems this brings, and how to preserve the integrity of the network. There is a rising demand from the market on Skanova to be able to offer integrated and useful services via their network. Examples of such services are Web Controlled Call Forwarding and Virtual Call Centres. Until now, these services have been implemented with the Intelligent Network concept which is a technology for concentrating the service logic in the telephone network to centralised service platforms within the network operator’s domain. Developing new services in this environment is expensive and therefore, Skanova wants to open the network for third party service providers. The opening of the network is enabled by the introduction of a gateway implementing the open service interface Parlay. The crucial point when opening the network for third party service providers is to maintain the integrity of the network. Parlay is an object oriented Application Programming Interface that enables a third party service access to core network resources in a controlled manner. The authors’ definition of network integrity is: “the ability of a network to steadily remain in a safe state, while performing according to the expectations and specifications of its owner, i.e. delivering the expected functionality and providing means to charge for utilised network resources”. The thesis describes a few services implemented via the Parlay interface and points out examples of activities in these services that may jeopardise the integrity of the network. The described activities belong to one of the two categories: Call Control Functionality or Lack of Charging Instruments. The thesis also describes two important methods for addressing encountered integrity problems. The methods are: Parlay Service Level Agreement and Policy Management.</p> Finally, the solutions are compared and the conclusion is that Policy Management is a conformable and flexible method for addressing lots of integrity problems and that these are important qualities, since new integrity problems will arise all the time.

In this dissertation, we address the problem of vagueness in traditional legal contracts by presenting novel methodologies that aid in the paradigm shift from traditional legal contracts to smart contracts. We discuss key enabling technologies that assist in converting the traditional natural language legal contract, which is full of vague words, phrases, and sentences to the blockchain-based precise smart contract, including metrics evaluation during our conversion experiment. To address the challenge of this contract-transformation process, we propose four novel proof-of-concept approaches that take vagueness and different possible interpretations into significant consideration, where we experiment with popular vendors' existing vague legal contracts. We show through experiments that our proposed methodologies are able to study the degree of vagueness in every interpretation and demonstrate which vendor's translated-smart contract can be more accurate, optimized, and have a lesser degree of vagueness. We also incorporated the method of fuzzy logic inside the blockchain-based smart contract, to successfully model the semantics of linguistic expressions. Our experiments and results show that the smart contract with the higher degrees of truth can be very complex technically but more accurate at the same time. By using fuzzy logic inside a smart contract, it becomes easier to solve the problem of contractual ambiguities as well as expedite the process of claiming compensation when implemented in a blockchain-based smart contract.

The recent emergence and rapid advancement of Cloud Computing (CC) infrastructure and services have made outsourcing Information Technology (IT) and digital services to Cloud Providers (CPs) attractive. Cloud offerings enable reduction in IT resources (hardware, software, services, support, and staffing), and provide flexibility and agility in resource allocation, data and resource delivery, fault-tolerance, and scalability. However, the current standards and guidelines adopted by many CPs are tailored to address functionality (such as availability, speed, and utilization) and design requirements (such as integration), rather than protection against cyber-attacks and associated security issues. In order to achieve sustainable trust for cloud services with minimal risks and impact on cloud customers, appropriate cloud information security models are required. The research described in this dissertation details the processes adopted for the development and implementation of an integrated information security cloud based approach to cloud service models. This involves detailed investigation into the inherent information security deficiencies identified in the existing cloud service models, service agreements, and compliance issues. The research conducted was a multidisciplinary in nature, with detailed investigations on factors such as people, technology, security, privacy, and compliance involved in cloud risk assessment to ensure all aspects are addressed in holistic and well-structured models. The primary research objectives for this dissertation are investigated through a series of scientific papers centered on these key research disciplines. The assessment of information security, privacy, and compliance implementations in a cloud environment is described in Chapters two, three, four, and five. Paper 1 (CCIPS: A Cooperative Intrusion Detection and Prevention Framework for Cloud Services) outlines a framework for detecting and preventing known and zero-day threats targeting cloud computing networks. This framework forms the basis for implementing enhanced threat detection and prevention via behavioral and anomaly data analysis. Paper 2 (A Trusted CCIPS Framework) extends the work of cooperative intrusion detection and prevention to enable trusted delivery of cloud services. The trusted CCIPS model details and justifies the multi-layer approach to enhance the performance and efficiency of detecting and preventing cloud threats. Paper 3 (SOCaaS: Security Operations Center as a Service for Cloud Computing Environments) describes the need for a trusted third party to perform real-time monitoring of cloud services to ensure compliance with security requirements by suggesting a security operations center system architecture. Paper 4 (SecSLA: A Proactive and Secure Service Level Agreement Framework for Cloud Services) identifies the necessary cloud security and privacy controls that need to be addressed in the contractual agreements, i.e. service level agreements (SLAs), between CPs and their customers. Papers five, six, seven, and eight (Chapters 6 – 9) focus on addressing and reducing the risk issues resulting from poor assessment to the adoption of cloud services and the factors that influence such as migration. The investigation of cloud-specific information security risk management and migration readiness frameworks, detailed in Paper 5 (An Effective Risk Management Framework for Cloud Computing Services) and Paper 6 (Information Security, Privacy, and Compliance Readiness Model) was achieved through extensive consideration of all possible factors obtained from different studies. An analysis of the results indicates that several key factors, including risk tolerance, can significantly influence the migration decision to cloud technology. An additional issue found during this research in assessing the readiness of an organization to move to the cloud is the necessity to ensure that the cloud service provider is actually with information security, privacy, and compliance (ISPC) requirements. This investigation is extended in Paper 7 (A Practical Life Cycle Approach for Cloud based Information Security) to include the six phases of creating proactive cloud information security systems beginning with initial design, through the development, implementation, operations and maintenance. The inherent difficulty in identifying ISPC compliant cloud technology is resolved by employing a tracking method, namely the eligibility and verification system presented in Paper 8 (Cloud Services Information Security and Privacy Eligibility and Verification System). Finally, Paper 9 (A Case Study of Migration to a Compliant Cloud Technology) describes the actual implementation of the proposed frameworks and models to help the decision making process faced by the Saudi financial agency in migrating their IT services to the cloud. Together these models and frameworks suggest that the threats and risks associated with cloud services are continuously changing and more importantly, increasing in complexity and sophistication. They contribute to making stronger cloud based information security, privacy, and compliance technological frameworks. The outcomes obtained significantly contribute to best practices in ensuring information security controls are addressed, monitoring, enforced, and compliant with relevant regulations. / Graduate / 0984 / 0790 / fahd333@gmail.com