In widely distributed systems generally, and in science-oriented Grids in particular, software, CPU time, storage, etc., are treated as “services” – they can be allocated and used with service guarantees that allows them to be integrated into systems that perform complex tasks. Network communication is currently not a service – it is provided, in general, as a “best effort” capability with no guarantees and only statistical predictability.

In order for Grids (and most types of systems with widely distributed components) to be successful in performing the sustained, complex tasks of large-scale science – e.g., the multi-disciplinary simulation of next generation climate modeling and management and analysis of the petabytes of data that will come from the next generation of scientific instrument (which is very soon for the LHC at CERN) – networks must provide communication capability that is service-oriented: That is it must be configurable, schedulable, predictable, and reliable. In order to accomplish this, the research and education network community is undertaking a strategy that involves changes in network architecture to support multiple classes of service; development and deployment of service-oriented communication services, and; monitoring and reporting in a form that is directly useful to the application-oriented system so that it may adapt to communications failures.

In this paper we describe ESnet's approach to each of these – an approach that is part of an international community effort to have intra-distributed system communication be based on a service-oriented capability.