Showing papers on "Service abstraction published in 2002"

G-QOSM: Grid Service Discovery Using QoS Properties

Abstract: We extend the service abstraction in the Open Grid Services Architecture~\cite{ogsa} for Quality of Service (QoS) properties. The realization of QoS often requires mechanisms such as advance or on-demand reservation of resources, varying in type and implementation, and independently controlled and monitored. Foster et al. propose the GARA~\cite{FostKessl99} architecture. The GARA library provides a restricted representation scheme for encoding resource properties and the associated monitoring of Service Level Agreements (SLAs). Our focus is on the application layer, whereby a given service may indicate the QoS properties it can offer, or where a~service may search for other services based on particular QoS properties.

Creating, modifying and storing service abstractions and role abstractions representing one or more packet rules

Abstract: The present invention provides a method and system for controlling usage of network resources on a communications network. The method comprising acts of: (a) creating one or more packet rules for analyzing packets received at one or more devices of the communications network, each rule including a condition and action to be taken if a packet received at a device satisfies the condition; and (b) creating one or more service abstractions associated with a user of the communication network, each service abstraction representing a named set of one or more of the packet rules. In some embodiments one or more role abstractions may be created, each role abstraction representing a role of a user with respect to the communications network, and each role abstraction including a set of one or more packet rules, and possibly one or more service abstractions.

Integrated Service Deployment for Active Networks

Abstract: A key feature of active networks is the capability to dynamically deploy services. In this paper, we present a scheme to classify service deployment mechanisms of existing or future active network architectures. Distributed algorithms (services), as being implemented in active networks, can be described based on active packets or as distributed programs running on active nodes. Although both programming models are basically equivalent, some services are more naturally implemented in either way. This paper proposes an active node architecture that supports the implementation and deployment of services according to both programming models. We point out that a combination of in-band and out-of-band service deployment is needed to dynamically deploy services implemented in either model. Furthermore, we argue that composing services from service logic implemented in either programming model is beneficial for the design of efficient and flexible services. We reason that a service abstraction in the form of a service description language is necessary to cope with real world scenarios.

XML-Based Dynamic Content Generation and Conversion for the Multimedia Home Platform

Abstract: Many systems gather content from multiple input sources and provide it to multiple output channels. Usually content has to be (partly) generated, and content has to be converted to different formats. In this paper, we will discuss the domain of digital content broadcasting with the Multimedia Home Platform (MHP) as a case study do- main. However, there are other domains that require con- tent generation and conversion as well, such as web engi- neering and content management. As a solution, we will present a generic XML-based architecture for dynamic con- tent generation and conversion. It provides content convert- ers for multiple input and output formats. Content format templates, fragments, and content format builders are alter- natives for dynamic content generation. Page templates are used to impose common styles and portal layouts for inter- dependent content. A Service Abstraction Layer supports service-based integration of different new media platforms.

ActiveCast: toward application-friendly active network services

Abstract: The next step in the evolution of active networks - one that will support radical new uses of the network and increased scalability - is to package the power of a programmable network platform into customizable active services that are easy for applications to use. The Activecast project has developed and is evaluating a set of active services that will not only enhance the "application-friendliness" of active networks, but will also improve the scalability and usability of networks in general. This paper discusses the challenges of programming active networks and then presents four new active network services, PAM-cast, Concast, ESP, and LWP, that simplify the task of programming active networks. PAMcast services allow messages to be sent to any node(s) satisfying a set of user-supplied selection criteria. The Concast service provides the logical inverse of multicast, gathering and merging data from a set of senders. Finally, the ESP and LWP services provide extremely lightweight building-blocks on which additional higher-level semantic services can be constructed. For each service, we describe the service abstraction, the ways in which users can customize the service, and its ease of use (i.e., how the customized service is automatically distributed across and "programmed" into the network on the user's behalf). We also present results from simulation models and actual implementations of the new services that demonstrate the scalability and performance of the services.