NFV at Edge Experiment by Politecnico of Turin Current solutions for Network Functions Virtualization (NFV) leverage the advantages of IT virtualization to install and operate virtual network functions (NFs) in (remote) data centers. However, this may not be appropriate in some specific deployment scenarios due to (a) possible large latency, (b) limited bandwidth between the end-user and the data center, (c) reliability issues. In these conditions, it may be more appropriate to exploit the existing computing/networking resources at the edge of the network in addition to traditional cloud-based infrastructures, potentially instantiating a service that spans across multiple infrastructure domains, such as a domestic CPE and a remote data center. This experiment, “Network Functions Virtualization at the Edge of the Network” (NFV@EDGE) aimed at extending the available NFV infrastructure available in SoftFIRE with the capability to control resource-constrained devices, such as home gateways, which are very common at the edge of the network. In this way, an overarching orchestrator can create a complex chain of services encompassing network functions running either at the edge or in the cloud, hence bringing in the benefits of edge-based services (e.g., reduced latency, no last-mile bandwidth bottleneck, better reliability) with the ones of cloud-based services (e.g., scalability, efficiency, economy of scale). NFV@EDGE has achieved its objectives by integrating a new NFV-capable platform, the Universal Node (UN), under the OpenBaton (OB) toolkit. The UN is a compact software orchestrator targeted to resource-limited devices such as domestic/SOHO residential gateways. Its integration with SoftFIRE enabled OpenBaton to create complex NFV services by instantiating the required NFs partly on edge-located nodes and partly on data centers, in a transparent way with respect to the service requester. Finally, NFV@EDGE has validated the proposed approach by running a set of experiments on the SoftFIRE infrastructure, simulating remote tenants asking for NFV services in different topological conditions and evaluating the achieved performance with and without edge-based nodes, in order to assess the benefits of edge-based services on a real geographically distributed infrastructure. The experiment (i) proved that the integration is possible, hence confirming the flexibility of both the OpenBaton and Universal Node platforms, (ii) demonstrated the advantages, in terms of throughput and latency, of deploying edge-based NFV services in specific use cases, (iii) confirms the appropriateness of the SoftFIRE testbed that was used to derive measurements in a real, geographically distributed environment. Finally, (iv) it shows that the NFV technology is not yet mature for immediate deployment, as confirmed by the several (mostly manual) configuration customizations that are required to make running a service that spans across multiple infrastructure domains, such as an edge-based CPE and a cloud-based OpenStack data center, and that can represent the starting point for a possible future work.
