# Probabilistic QoS-aware Placement of VNF chains at the Edge

## TL;DR

This paper introduces EdgeUsher, a declarative approach that optimally places VNF chains in Cloud-Edge environments by considering probabilistic infrastructure variations to meet diverse deployment and communication requirements.

## Contribution

EdgeUsher is the first solution to incorporate probabilistic models for dynamic infrastructure variations in VNF placement at the Edge.

## Key findings

- Successfully determines all eligible placements satisfying requirements.
- Models infrastructure variations using probability distributions.
- Ensures placement robustness against dynamic changes.

## Abstract

Deploying IoT-enabled Virtual Network Function (VNF) chains to Cloud-Edge infrastructures requires determining a placement for each VNF that satisfies all set deployment requirements as well as a software-defined routing of traffic flows between consecutive functions that meets all set communication requirements. In this article, we present a declarative solution, EdgeUsher, to the problem of how to best place VNF chains to Cloud-Edge infrastructures. EdgeUsher can determine all eligible placements for a set of VNF chains to a Cloud-Edge infrastructure so to satisfy all of their hardware, IoT, security, bandwidth, and latency requirements. It exploits probability distributions to model the dynamic variations in the available Cloud-Edge infrastructure, and to assess output eligible placements against those variations.