Network Function Virtualization as a Service for multi-tenant software defined networks

In this paper, we assess the performance of a Network Function Virtualization as a Service (NFVaaS) platform when deployed using a unikernel minimal operating system and running on top of a network hypervisor for software defined networks (SDNs). Our NFVaaS infrastructure is built on top of the unikernel minimal operating system ClickOS and the OpenVirteX network hypervisor, which enforces network isolation in multi-tenant SDN networks. Our experimental results demonstrate the effectiveness of using ClickOS when deploying and moving individual virtual network functions (VNFs) in multi-tenant SDN networks. We also identified the main limitations in terms of number of active VNFs that can be deployed at the same time, as well as the maximum memory size that can be allocated to each VNF in respect to the underlying available hardware resources. Moreover, we performed a thorough analysis and assessment of the impact of VNFs' placement on network performance, especially when multiple VNFs are organized as a service chain to create more sophisticated network functionalities.