Benefits of conditional FPGA provisioning for virtualized network functions
Leonhard Nobach, Benedikt Rudolph, David Hausheer · 2017
Network Functions Virtualization (NFV) stands for a major paradigm shift in computer networks. Despite the flexibility improvements which NFV offers, the commonly used COTS processors show performance limitations compared to specialized circuits. A trade-off can be achieved by reconfigurable hardware like FPGAs, which provide high, guaranteed performance and flexibility. However, FPGAs are costly, and the network function resources - programmable gates - have a limited ability to scale in, as they must stay occupied even if the performance requirements are currently low. In this work, we envision to evaluate the advantages that arise from a dynamic provisioning of FPGA resources on the datapath of virtual network functions. In a first step, we evaluate performance characteristics of FPGA and COTS processor resources running an example DPI NF. Given a lease cost model, we furthermore analytically evaluate the advantage of dynamically selecting FPGA or COTS processor resources for this NF, depending on the current performance demands. Our evaluation shows that we can save up to 39% of costs by a dynamic provisioning based on the expected load.