A Service Composition Model for Automatically Switched Transport Networks

Grid applications in wide area networks (WANs) can benefit from the QoS-enabled dynamic connectivity offered by the automatically switched transport network (ASTN). To exploit this benefit, grid middleware must be able to request ASTN network services with a level of abstraction that do not require the knowledge of the network implementation details. The service oriented automatically switched transport network (SO-ASTN) is an ASTN architectural enhancement able to export such network services by composing the ASTN connectivity services. This work presents a service composition model (SCM) and a relevant service composition language (SCL) suitable for SO-ASTN. The principal novelty of the proposed SCM consists in the reuse of the intelligent network service composition paradigm in conjunction with the XML technologies used in the Web services. The SCL, based on the ontology theory, can describe not only the composition of the ASTN connectivity but also the modality of the service process execution. The proposed SCM and SCL are then experimentally validated on a testbed in which a grid application requests the topology of a virtual private network (VPN)