Megalos - A Scalable Architecture for the Virtualization of Network Scenarios.

We introduce an ETSI NFV compliant, scalable, and distributed architecture, called Megalos, that supports the implementation of virtual network scenarios consisting of virtual devices (VNFs) where each VNF may have several L2 interfaces assigned to virtual LANs. We rely on Docker containers to realize VNFs and we leverage Kubernetes for the management of the nodes of a distributed cluster. Our architecture guarantees the segregation of each virtual LAN traffic from the traffic of other LANs, from the cluster traffic, and from Internet traffic. Also, a packet is only sent to the cluster node containing the recipient VNF. The allocation of the VNFs to the nodes of the cluster is performed by Megalos Scheduler, taking into account the network topology in order to reduce the traffic among nodes. We produce an example application where we emulate a large network scenario, with thousands of VNFs and LANs, on a small cluster of 50 nodes. Finally, we experimentally show the scalability potential of Megalos by measuring the overhead of the distributed environment and of its signaling protocols.