In the last few years, there has been a remarkable growth in the number of data centers, which represent one of the leading sources of increased business data traffic on the Internet. An effect of the growing scale and the wide use of data centers is the dramatic increase of power consumption, with significant consequences both in terms of environmental and operational costs. Hence, energy awareness has become one of the major design constraints for Cloud infrastructures. In order to face these challenges, a new generation of energy-efficient and ecosustainable network infrastructures is needed. In this work, a novel energy-aware resource orchestration framework for distributed Cloud infrastructures is introduced, in order to manage both network and IT resources in a typical optical backbone. A high-level overview of the system architecture is provided by focusing on the definition of the different layers of the whole infrastructure, and introducing the Path Computation Element, which is the key component of the proposed architecture. The aim is to explain how both network and IT resources can be managed while, at the same time, the overall power consumption is being minimized and QoS requirements are satisfied. Finally, a green migration plan that is obtained by applying Virtual Machine relocation algorithms is discussed, in order to dynamically react to the fluctuating resource requirements of the VMs