Abstract
In the last years, several projects are emerged with the aim to addressing the challenge of providing solutions for deployment, monitoring, adaptation, and management of clouds belonging to different enterprises/organisations. In such scenarios the network connectivity is one of the key factors. SDN technologies represent a good solution to face this challenge. Separating the control plane from the data plan, they can supply the cloud provider with the opportunity to specify on-the fly both the network topologies and routing schemes, guaranteeing, at same time, specific level of isolation. ASSDN, the framework presented in this paper, represents the first attempt to face this kind of issue. Driving the SDN controllers of all the Network Providers involved, it allows to create, handle and monitor virtual networks that are able to span across several heterogeneous cloud environments so to guarantee specific level of QoS.