# The Road to BOFUSS: The Basic OpenFlow User-space Software Switch

## TL;DR

This paper provides a comprehensive overview of BOFUSS, a user-space OpenFlow switch, highlighting its architecture, uses, and performance trade-offs, serving as a reference for researchers needing customizable SDN switch solutions.

## Contribution

It offers the first detailed reference documentation and survey of BOFUSS, emphasizing its role as a customizable alternative to kernel-based switches like OVS.

## Key findings

- BOFUSS is widely used in research for SDN development.
- Enhancements from the BEBA project improved BOFUSS performance.
- BOFUSS offers features missing in OVS and is easily modifiable.

## Abstract

Software switches are pivotal in the Software-Defined Networking (SDN) paradigm, particularly in the early phases of development, deployment and testing. Currently, the most popular one is Open vSwitch (OVS), leveraged in many production-based environments. However, due to its kernel-based nature, OVS is typically complex to modify when additional features or adaptation is required. To this regard, a simpler user-space is key to perform these modifications. In this article, we present a rich overview of BOFUSS, the basic OpenFlow user-space software switch. BOFUSS has been widely used in the research community for diverse reasons, but it lacked a proper reference document. For this purpose, we describe the switch, its history, architecture, uses cases and evaluation, together with a survey of works that leverage this switch. The main goal is to provide a comprehensive overview of the switch and its characteristics. Although the original BOFUSS is not expected to surpass the high performance of OVS, it is a useful complementary artifact that provides some OpenFlow features missing in OVS and it can be easily modified for extended functionality. Moreover, enhancements provided by the BEBA project brought the performance from BOFUSS close to OVS. In any case, this paper sheds light to researchers looking for the trade-offs between performance and customization of BOFUSS.