Network Virtualization

Network Virtualization is a promising development to provide an innovation platform in today's networks [1]. It is basically a combination and extension of the existing network virtualization techniques such as Virtual LANs, Virtual Routing and Forwarding, and Virtual Private Networks into a system which allows the creation of Virtual Networks. Virtual Networks can have topologies that are not restricted by the physical networks they spawn from.  They can even have virtual nodes, nodes that do not appear in the original network. On top of this, the nodes provide some degree of programmability, making them flexible and easy to upgrade [2].

It has implications in many areas of networking. On the business side new business models are possible, for example a new type of ISP-like organization which, instead of providing single-point access to the Internet or point-to-point VPNs, provides an entire virtual network that the customer has full control over. Similarly it may allow sharing of expensive infrastructure between multiple operators, making network deployment in certain areas feasible where it previously has been to costly for a single operator to install the necessary equipment [3].

At the technical side many new possibilities arise. For example, by creating separate Virtual Networks for different services the topology and protocols running in the different networks may be optimized, per Virtual Network. The ability to create abstract nodes, nodes appearing as single nodes although they consist of multiple nodes and links, simplifies network configuration and end-node mobility, e.g. by simply reducing the amount of manual configuration that is necessary.

In OpenFlow some degree of network virtualization may be provided through the FlowVisor mechanism [4], however, it is not rigid enough to be called carrier grade. In the project we investigate and implement methods to improve OpenFlow-based virtualization: this could for example be methods for strictly isolating the different Virtual Networks from each other.