Predictable Bandwidth Slicing with Open vSwitch

TL;DR

This paper investigates how switch configurations affect bandwidth slicing and latency predictability in software switches, highlighting the importance of implementation details for deterministic performance in edge computing.

Contribution

It provides an analysis of how different bandwidth slicing mechanisms and schedulers in Open vSwitch impact performance predictability.

Findings

Latency depends on slicing mechanism implementation

Different schedulers focus on different performance aspects

Deterministic performance is achievable with proper configuration

Abstract

Software switching, a.k.a virtual switching, plays a vital role in network virtualization and network function virtualization, enhances configurability, and reduces deployment and operational costs. Software switching also facilitates the development of edge and fog computing networks by allowing the use of commodity hardware for both data processing and packet switching. Despite these benefits, characterizing and ensuring deterministic performance with software switches is harder, compared to physical switching appliances. In particular, achieving deterministic performance is essential to adopt software switching in mission-critical applications, especially those deployed in edge and fog computing architectures. In this paper, we study the impact of switch configurations on bandwidth slicing and predictable packet latency. We demonstrate that latency and predictability are dependent on the implementation of the bandwidth slicing mechanism and that the packet schedulers used in OVS Kernel-Path and OVS-DPDK each focus on different aspects of switching performance.