Load Balancing of Virtual Network Functions through Packet Delegation

Abstract

Network Function Virtualization is a promising technology that can provide complex packet processing capabilities through Virtual Network Function (VNF) chains. Service Function Chaining aims to facilitate the management of these chains, typically through centralized management and orchestration, which perform inadequately when operating under heavy load, as they require the exchange of a significant amount of packets and they often optimize for network-wide metrics, potentially providing subpar performance to a few individuals. To address these shortcomings, a packet delegation mechanism is proposed in this paper, which can be integrated into the lifecycle managers of VNFs and serves as a load sharing mechanism redirecting traffic from VNFs under heavy load to other servers. Additionally, the prioritization of delegated packets is proposed to reduce the delay overhead that is introduced by the additional hops that delegated packets may need to traverse. The packet delegation mechanism is analytically studied under certain assumptions using queueing theory and its performance is evaluated through experimentation in a simulation setting. The acquired results validate the analysis, which indicates that packet delegation can effectively redirect traffic from overburdened VNFs and reduce end-to-end delay, while utilizing purely local information.