Bring Functions Back to the Network: A Measurement Study

Network Function Virtualization (NFV) is envisioned to provide the foundation for a dynamic, high-performance multi-layer network architecture. With NFV, running network functions on general-purpose hardware is supposed to lower network latency due to reduced propagation delay. The trade-off, however, is in impaired reliability and increased processing latency, which could negatively affect Quality of Service (QoS) and Quality of Experience (QoE). We investigate the tradeoff via a comprehensive measurement study exploiting a high-precision measurement method on a carrier-grade Cisco Catalyst 9500 Series switch, which provides enhanced computing capability via lightweight containerization. Baseline results on packet forwarding latency confirm that software-based forwarding is inferior to the hardware pendant. Subsequently, we deploy a more realistic application with an example for network coding and introduce a new metric, re-coding opportunities. Our study identifies a superior performance of generic hardware, but also shows advantages of in-network computing for latency-tolerable scenarios.