Distributed applications or workflows need to access and use compute, storage and network resources simultaneously or chronologically coordinated respectively. Examples are distributed multi-physics simulations that use the combined computational performance and data storage of multiple clusters. A coordinated reservation and allocation of the resources is a prerequisite for the efficient use of such resources. This contribution describes the components of a system that provides Grid users with this functionality. The Grid middleware UNICORE is extended to access a MetaScheduling Service (MSS) performing orchestration of resources of different administrative domains, using advance reservation capability of local resource management systems (RMS) - including network connections for which ARGON serves as RMS. ARGON leverages Bandwidth on Demand, a cornerstone of next generation Grid enabled optical networks rendering the network to a first class Grid resource.