Cloud and network service orchestration in Software Defined Data Centers

Cloud Data Centers are becoming a more and more important reality nowadays, as more and more services are being offered in the form of Cloud resources. In order to accommodate as many requests as possible, Data Centers typically deploy oversubscription, which requires a thoughtfully calibrated usage of the computing and network resources of the system. We especially need to re-think the usage of network resources, as the kinds of demands from applications we see today have more stringent network requirements than in the past. The Software-Defined Network paradigm offers new tools to manage the network in agile, flexible ways, according to specific needs. It enables to build new customized functions in order, for example, to monitor the instantaneous load of traffic, slice the network, route each flow according to specific policies that can be modified accordingly with the needs of the system. In this paper we present an orchestrator for Software-Defined Data Center, and the strategies used to allocate Virtual Machines, basing our decisions on the current state of the system.