It is envisaged that services and applications will migrate to a cloud-computing paradigm where thin-clients on userdevices access, over the network, applications hosted in data centers by application service providers. Examples are cloudbased gaming applications and cloud-supported virtual desktops. For good performance and efficiency, it is critical that these services are delivered from locations that are the best for the current (dynamically changing) set of users. To achieve this, we expect that services will be hosted on virtual machines in interconnected data centers and that these virtual machines will migrate dynamically to locations bestsuited for the current user population. A basic network infrastructure need then is the ability to migrate virtual machines across multiple networks without losing service continuity. In this paper, we develop mechanisms to accomplish this using a network-virtualization architecture that relies on a set of distributed forwarding elements with centralized control (borrowing on several recent proposals in a similar vein). We describe a preliminary prototype system, built using Openflow components, that demonstrates the feasibility of this architecture in enabling seamless migration of virtual machines and in enhancing delivery of cloud-based services.
Hao et al proposed a new approach which enables VM migration across multiple networks without losing service continuity REF .
Enhancing dynamic cloud-based services using network virtualization
CCRV
Computer Science