Service Level Agreements Management Research Articles

Utility computing SLA management based upon business objectives

It has become increasingly desirable for companies worldwide to outsource their complex e-business infrastructure under the utility computing paradigm by means of service level agreements (SLAs). A successful utility computing provider must be able not only to satisfy its customers' demand for high service-quality standards, but also to fulfill its service-quality commitments based upon business objectives (e.g., cost-effectively minimizing the exposed business impact of service level violations). This paper presents the design rationale of a business-objectives-based utility computing SLA management system, called SAM, along with implementation experiences.

Managing service-level agreements in metro ethernet networks using backpressure

Ethernet, which has long been used for local area networks (LANs), is increasingly being employed for metropolitan area networks (MANs). Because it is familiar, simple, and cost-effective, it is becoming popular as a means of transporting data in a MAN. A prerequisite for providing different levels of service in a MAN is the ability to support and maintain service-level agreements (SLAs). Proper management of SLAs ensures that users do not violate their contracts and makes it possible to guarantee quality of service (QoS). Such management requires support for traffic flow control, monitoring, and policing. This paper presents a novel Ethernet traffic-policing mechanism based on backpressure and able to provide feedback to an end user or access network when SLAs are violated, instead of simply dropping packets. The performance of this mechanism is analyzed by means of tests. The tests focus on the effects of the mechanism on throughput and fairness for transmission control protocol (TCP) traffic and on jitter and packet drops for user datagram protocol (UDP) multimedia traffic. © 2003 Lucent Technologies Inc.

Cadenus: creation and deployment of end-user services in premium IP networks

Current trends in the information and communications technology industry clearly indicate the existence of a business requirement for a market-enabling technology that allows network operators to interact with users in a seamless, transparent manner for the sale and delivery of a wide range of services with guaranteed quality of service. In this context the need arises for the dynamic creation, configuration and delivery of services with QoS guarantees via the automated management of service level agreements. The aim of the Cadenus project is to bring theoretical and practical contributions to this area by defining a framework for the provisioning of advanced communication services in premium IP networks. Such networks might be characterized by a high degree of complexity, in terms not only of scale, but also of number of operators and technological heterogeneity. Our contribution is twofold, comprising both the design of the proposed framework and its actual implementation. An innovative approach was taken to framework design, based on the concept of mediation. With respect to the framework implementation, an example illustrating the realization of a virtual private network scenario is presented.

The WSLA Framework: Specifying and Monitoring Service Level Agreements for Web Services

We describe a novel framework for specifying and monitoring Service Level Agreements (SLA) for Web Services. SLA monitoring and enforcement become increasingly important in a Web Service environment where enterprise applications and services rely on services that may be subscribed dynamically and on-demand. For economic and practical reasons, we want an automated provisioning process for both the service itself as well as the SLA managment system that measures and monitors the QoS parameters, checks the agreed-upon service levels, and reports violations to the authorized parties involved in the SLA management process. Our approach to these issues is presented in this paper. The Web Service Level Agreement (WSLA) framework is targeted at defining and monitoring SLAs for Web Services. Although WSLA has been designed for a Web Services environment, it is applicable as well to any inter-domain management scenario, such as business process and service management, or the management of networks, systems and applications in general. The WSLA framework consists of a flexible and extensible language based on XML Schema and a runtime architecture comprising several SLA monitoring services, which may be outsourced to third parties to ensure a maximum of objectivity. WSLA enables service customers and providers to unambiguously define a wide variety of SLAs, specify the SLA parameters and the way they are measured, and relate them to managed resource instrumentations. Upon receipt of an SLA specification, the WSLA monitoring services are automatically configured to enforce the SLA. An implementation of the WSLA framework, termed SLA Compliance Monitor, is publicly available as part of the IBM Web Services Toolkit.

The structure and management of service level agreements in networks

The paper proposes a structure for quality-of-service (QoS)-centered service level agreements (SLA), and a framework for their real-time management in multiservice packet networks. The SLA is structured to be fair to both parties, the service provider and their customer. The SLA considered here are for QoS assured delivery of aggregate bandwidth from ingress to egress nodes; however, the control and signaling is for the more granular flows or calls. A SLA monitoring scheme is presented in which revenue is generated by the admission of flows into the network, and penalty incurred when flows are lost in periods when the service provider is not SLA compliant. In the SLA management scheme proposed, the results of a prior off-line design are used, in conjunction with measurements taken locally at ingress nodes, to classify the loading status of routes. The routing and resource management are based on virtual partitioning and its supporting mechanism of bandwidth protection. The effectiveness of SLA management is measured by the robustness in performance in the presence of substantial diversity in actual traffic conditions. A simulation testbed called D'ARTAGNAN has been built from which we report numerical results for a case study. The results show that the SLA management scheme is robust, fair and efficient over a broad range of traffic conditions.

Management of service level agreements for multimedia Internet service using a utility model

The efficient management of a quality level of Internet service is becoming increasingly important to both customers and service providers. This article describes how service level agreements for multimedia Internet service can be managed and controlled. We first present a literature survey on the problems of SLA management: SLA parameter definition, SLA measurement, and QoS management. We present a utility model to capture the management and control aspects of SLAs for multimedia Internet service. This utility model has been used in microeconomics theory, but here we have applied it to SLA management. This model provides a computationally feasible solution for admission control and quality adaptation for multimedia Internet service and SLA management. It also allows management policies to be flexibly expressed by service providers. Finally, we apply the utility model to the SLA management of VoIP service and describe how to use it for admission control, dynamic quality adaptation, and resource allocation for SLA assurance.

SLA management in federated environments

Increasingly, Internet services are being deployed over an infrastructure that spans multiple control domains. These services require cooperation between multiple organizations, systems and entities. Currently, few standard mechanisms exist to share selective management information between the various service providers or between service providers and their customers. Such mechanisms are necessary for end-to-end service management and diagnosis as well as for ensuring the service level obligations between a service provider and its customers or partners. This paper describes an architecture that uses contracts based on service level agreements (SLAs) to share selective management information across administrative boundaries. The design of a prototype implementation for automatically measuring, monitoring, and verifying service level agreements for Internet services is also described.

Managing service level agreements

Service level agreements are increasingly being used in enterprise networks and are contracts that specify the performance parameters within which a network service is provided. In this article their application, preparation, and effects on IT departments are considered. Copyright © 1999 John Wiley & Sons, Ltd.

Managing service level agreements

Managing service level agreements

Integrated TMN Service Management

The deregulation of the global telecommunication industry has seen a change in the business and operational environment in which services are deployed and managed. The requirements have intensified to provide a management framework for telecommunication networks and services across multiple technology domains and using multiple management technologies. This paper describes an integrated TMN service management architecture that provides an environment for different service management functions and different management domains to be integrated. To further substantiate this architecture, a system was built to demonstrate the integration concepts. The research and development work reported in this paper focuses on the following two aspects of integration: first the integration between TMN network and service management functions; and next the integration between different service management functions. A proof of concept system was developed to demonstrate such integration. It consists of the following components: Generic service ordering and provisioning; connection management based on a generic network model concept; and service management based upon service level agreement management and customer service management concepts. This paper reports this work and the experiences gained from this research.