Post-fault restoration of service function chains in fog networks

The network function virtualization (NFV) paradigm is rapidly being adopted by enterprises and service providers as an alternative to proprietary hardware. It enables virtual network functions (VNFs) to be embedded on commercial edge servers for the delivery of highly-specialized service function chains (SFCs). Here embedding SFC requests on fog computing supports clients with stringent delay requirements and contextual service requirements. Now one of the major challenges is the survivability of embedded service chains in fog computing, which may be compromised due to node, link, and application failures. These failures can disrupt service continuity and degrade the quality-of-service. Therefore, there is a demand for SFC provisioning to be more resilient, incorporating rapid restoration techniques that oppose proactive solutions that reserve backup paths, subsequently compromising network capacity. Hence, this paper presents heuristic methods for post-fault SFC restorations due to multiple failures in fog computing. These methods establish post-provisioning restoration for failed requests, known as end-to-end (E2E) and intermediate (IM) restoration, that aim to restore paths with the least delay and cost.