SFC Provisioning With Load Balancing Method in Multi-Tier Fog Networks

Network function virtualization (NFV) requires service function chain (SFC) provisioning on cloud or fog servers. Now fog nodes offers short provisioning times as compared to the cloud, albeit limited resources. This makes fog nodes vulnerable to saturation if users demand computation-intensive services, where offloading to the cloud is prohibited due to the prolonged delays. Hence, this letter proposes a novel SFC provisioning scheme for fog paradigms that achieves load balancing (LB) and redistribution between heavily- and lightly-loaded nodes, without exceeding delay bounds. The scheme features high admission rates and reduced delays versus prominent solutions such as standalone delay or load minimization methods.

I. Introduction

Fog computing [1] provides local services at reduced response times attributed to the shorter propagation delays as compared to the cloud core. This allows service providers to accommodate delay-sensitive applications by providing local computation, storage, and communication. These applications are presented by network functions and traditionally offered on dedicated legacy hardware. Instead, NFV [2] is leveraged to provide containerized virtual network functions (VNF) over fog nodes. This allows flexible deployment of various VNF instances since a single node can run multiple VNFs. The latter often requires sequential instantiation to provide services, thus forming SFCs. Hence it is important to embed SFCs on fog nodes at reduced embedding time and high resource utilization.