ARP-P4: deep analysis of a hybrid SDN ARP-Path/P4-Runtime switch

Abstract

The Software-Defined Networking (SDN) architecture decouples the control plane from the data plane, but it does not explicitly state where the control should be located. This article analyses the benefits of maintaining the control as close as possible to the data plane, instead of the more traditional centralised control plane approach. To this purpose, it delves into the study of ARP-P4, a hybrid software switch defined by using the P4 language to facilitate its future use and deployment in P4 targets. Its hybrid properties come from supporting two complementary different ways of establishing paths: a centralised SDN approach based on P4-Runtime and a traditional distributed approach based on the ARP-Path protocol that obtains a similar performance to centralised solutions based on Equal Cost Multi-Path (ECMP) and Dijkstra. The results show the feasibility of hybrid devices that combine different forwarding paradigms without losing performance with respect to well-known solutions such as ECMP, and how their combined use can lead to enhance and scale communication networks.