Special issue on virtualization

Virtualization has always been an enabler for effi cient management in networking environments. The recent developments in hardware and software virtualization that emerged in the last few years now open new and very promising perspectives to more fl exible networks, paving the way for new advanced services. However, to enable these evolutions to become one of the core building blocks of the future Internet, many challenges still need to be addressed. In this special issue of the International Journal of Network Management, three papers present different approaches to virtualization and its utilization for improving networks and their management. The paper entited ‘Using Virtual Topologies to Manage Inter-domain QoS in Next Generation Networks’ by Madeira et al. proposes the virtualization of network topologies to ease inter-domain quality of service management. The paper entitled ‘Specifying and provisioning Virtual Infrastructures with HIPerNET’, by Anhalt et al., extends the model of virtualization to both computing resources and networks so as to enable full infrastructure virtualization. Finally, the paper entitled ‘Characterizing User-level Network Virtualization: Performance, Overheads and Limits’, by Tsugawa et al., provides a study on the performance of virtualized networks built as overlays among standard operating systems nodes. This special issue on ‘Network Virtualization and Its Management’ received ten submissions from around the world, out of which the three papers mentioned above have been selected. Every submitted paper has been reviewed by four experts from a committee composed of nine researchers in the fi eld.