Date Added: Jul 2010
Network virtualization is a promising abstraction technique, not only to optimize the utilization of network resources, but also to design and actually bring out completely novel network architectures and protocols. Such a virtual network consists of virtual nodes that are interconnected by virtual links. Thus the virtual network builds its own logical overlay structure on top of the physical "Substrate", i.e., the underlying real physical network. Virtual links are, however, mostly configured statically, or do not provide Quality-of-Service (QoS) guarantees along the entire substrate path or are limited to a specific administrative domain.