The effects of qos level degradation cost on provider selection and task allocation model in telecommunication networks

Firms acquire network capacity from multiple suppliers which offer different Quality of Service (QoS) levels. After acquisition, day-to-day operations such as video conferencing, voice over IP and data applications are allocated between these acquired capacities by considering QoS requirement of each operation. In optimal allocation scheme, it is generally assumed each operation has to be placed into resource that provides equal or higher QoS Level. Conversely, in this study it is showed that former allocation strategy may lead to suboptimal solutions depending upon penalty cost policy to charge degradation in QoS requirements. We model a cost minimization problem which includes three cost components namely capacity acquisition, opportunity and penalty due to loss in QoS

THE EFFECTS OF QOS LEVEL DEGRADATION COST ON PROVIDER SELECTION AND TASK ALLOCATION MODEL IN TELECOMMUNICATION NETWORKS

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The Effects of QoS Level Degradation Cost on Provider Selection and Task Allocation Model in Telecommunication Networks

─Abstract ─ Firms acquire network capacity from multiple suppliers which offer different Quality of Service (QoS) levels. After acquisition, day-to-day operations such as video conferencing, voice over IP and data applications are allocated between these acquired capacities by considering QoS requirement of each operation. In optimal allocation scheme, it is generally assumed each operation has to be placed into resource that provides equal or higher QoS Level. Conversely, in this study it is showed that former allocation strategy may lead to suboptimal solutions depending upon penalty cost policy to charge degradation in QoS requirements. We model a cost minimization problem which includes three cost components namely capacity acquisition, opportunity and penalty due to loss in QoS

Uncertainty and uncertainty tolerance in service provisioning

PhDService, in general term is a type of economic activity where the consumers utilize labour and/or expertise of others to perform a specific task. The birth and continued growth of the Internet provide a new medium for services to be delivered, and enable services to become widely and readily available. In recent years, the Internet has become an important platform to provide services to the end users. Service provisioning, In the context of computing, is the process of providing users with access to data and technology resources. In a perfect operating environment, the entities involved can expect the system will perform as intended or up to an accepted level of quality. Unfortunately, disruptions or failures can occur which can affect the operation of the service. Thus, the entities involved, in particular the service requester faces a situation whereby the service requester’s belief towards certain process in the service provisioning life cycle is affected, i.e. deviates from the actual truth. This situation whereby the service requester’s belief is affected is referred as an uncertainty. in this thesis, we discuss and explore the issue of uncertainty throughout the service provisioning life cycle and provide a measure to tolerate uncertainty in service provisioning offer through the application of subjective probability framework. This thesis provides several key contributions to address the uncertainty issues in service provision- Ing system in particular, for a service requester to overcome the negative consequence of uncertainty. The key contributions are: (1) introduction to the issue of uncertainty in service provisioning system, (2) a new classification scheme for uncertainties in service provisioning system, (3) a unified view of uncertainty in service provisioning system based on temporal classification, which is linked to service requester’s view, (4) a concept of uncertainty tolerance for service provisioning, (5) an approach and framework for automated uncertainty tolerance in service provisioning offer. The approach and framework for uncertainty tolerance in service provisioning offer presented in this thesis is evaluated through an empirical study. The result from the study shows the viability of the approach and framework of the uncertainty tolerance Mechanism through the application of subjective probability theory. The result also shows the positive outcome of the mechanism in term of higher cumulative utility, and better acceptance rate for the service requester.UNIMAS(Universiti Malaysia Sarawak) Government of Malaysi

Cost-Optimal Service Selection Based on Incident Patterns - A Service Level Engineering Approach

The assessment of services\u27 adverse business impact is a prerequisite for the determination of cost-optimal service offers. We suggest service incident patterns as an advanced form of quality measures describing a service\u27s characteristic incident behavior. We show that the knowledge about service incident patterns and the business impact induced by service incidents is required to determine the total business costs a service induces and develop the method for Cost-Optimal Service Selection

Developing a user-centric distributed middleware for SLA monitoring in SaaS cloud computing using RESTful services

One of the most important discussions in the cloud computing field is user satisfaction with the associated services. It is important to maintain trusted relationships between clients and providers, for customers who pay subscriptions to receive these services in a timely and accurate manner. Despite the overwhelming advantages of cloud services, clients sometimes have problems in service outage and resource failure. This is due to the failures that can happen in cloud servers, which cause outages to the received services. For example, the failure of Microsoft Office 365 on 18th of January 2016, caused email disruption which lasted for many days. New measures are needed to ensure that the contract signed between the two parties, known as a Service Level Agreement (SLA) has been adhered to. Measuring the quality of cloud computing provision from the client’s point of view is, therefore, essential in order to ensure that the service conforms to the level specified in the agreement; this is usually referred to as Quality of Experience. In recent years, there has been an increase shift in using Simple Object Access Protocol (SOAP) to Representational State Transfer (REST) technology as an alternative technology in cloud applications APIs development. However, there is a penchant in most of cloud monitoring solutions to use SOAP protocol in managing the monitoring process. This trend has drawn the attention to the need for using REST technology in transferring the monitored data between the provider side and the client side. This thesis addresses the problem of monitoring the quality of Software as a Service from the users’ perspective, and the need for developing a lightweight middleware for delivering the monitored data in Software as a Service cloud computing. The aim of this research is to propose a user centric approach for monitoring Software as a Service in cloud computing, and to reduce the overhead caused by the monitoring process. In order to achieve this aim, a user centric middleware capable of monitoring the Quality of Experience has been developed. The developed middleware is a Service Oriented middleware which uses RESTful web services and provides the monitoring process as an add-on service. A new approach was developed for embedding the SLA parameters in REST services through extending the HTTP messages and exploiting the HEAD and OPTIONS methods to transmit the monitored data and to send notifications about anySLA violations. This reduces the need to exchange extra monitoring messages between the two parties, and hence reduces the communication overhead. Furthermore, the estimation of the user satisfaction was implemented by developing a decision making approach to estimate the Quality of Experience value and to predict the effect of the SLA parameters and the Quality of Service (QoS) on the user satisfaction. Fuzzy logic techniques were employed in the decision making process.The developed middleware is called MonSLAR, for Monitoring SLA for Restful services in SaaS cloud computing environments. The middleware was implemented using the Java programming language, and tested successfully in a cloud environment to prove the proposed solution’s capability of transmitting the data using the REST methods, in addition to providing automated and real time feedback. MonSLAR uses a distributed monitoring architecture, which allows SLA parameters to be embedded in the requests and responses of the REST protocol. The proposed middleware was evaluated by measuring the overhead caused by using REST technology in terms of response time and message size and compared to existing techniques. The results revealed that the message size overhead of using REST is approximately five times less than the message size overhead caused by SOAP. Furthermore, the response time overhead of the monitoring process is comparable to the overhead caused by the available monitoring frameworks. To sum up, the proposed middleware will help to strengthen the relationship between the client and the provider by using real time notifications to the client about any degradation in the cloud services, using a lightweight middleware

Monitoring and Reputation Mechanisms for Service Level Agreements

A Service Level Agreement (SLA) is an electronic contract between a service user and a provider, and specifies the service to be provided, Quality of Service (QoS) properties that must be maintained by a provider during service provision (generally defined as a set of Service Level Objectives (SLOs)), and a set of penalty clauses specifying what happens when service providers fail to deliver the QoS agreed. Although significant work exists on how SLOs may be specified and monitored, not much work has focused on actually identifying how SLOs may be impacted by the choice of specific penalty clauses. A trusted mediator may be used to resolve conflicts between the parties involved. The objectives of this work are to: (i) identify classes of penalty clauses that can be associated with an SLA; (ii) define how to specify penalties in an extension of WS-Agreement; and (iii) specify to what extent penalty clauses can be enforced based on monitoring of an SLA