´Virtual organization´: a service-level resource management framework for distributed network infrastructures

The paper describes a management model for network service provisioning in which a service provider (SP) may maintain multiple protocol mechanisms to support its clientele. Client applications are presented with an abstract interface to these protocol mechanisms, through which service obligations may be prescribed. The management functions of SP track the changes and/or outages in network infrastructure resources in a highly dynamic setting, so that the service provisioning can be made resource-optimal. The management functions are based on a modular decomposition principle, which we refer to as ´virtual organization´ of protocol modules. In this paradigm, a service may be viewed as provided by multiple protocol modules, with the SP selecting one of these modules and instantiating it with appropriate parameters to meet the service obligations. The model allows dynamic switching from one protocol module to another, based on a notion of cost associated with the infrastructure resource usage for a given level of service provisioning. The paper provides the functional mechanisms to realize the switching from one protocol to another for a client-transparent service provisioning. These mechanisms are based on our management-oriented studies of different types of information networks (such as content distribution networks and QoS-controlled data connections). Our model of service management offers a methodology for SPs to achieve cost-effectiveness for their service offerings.