Analytical Modeling for Virtualized Network Functions

TL;DR

This paper introduces a flexible analytical queuing network model for virtualized network functions in 5G, validated through simulation and outperforming existing methods in accuracy and complexity.

Contribution

It presents a generic open queuing network model for VNFs that accurately estimates response times with low computational complexity.

Findings

Model has similar complexity to Jackson's networks

Estimation error around 10% for mean response time

Outperforms baseline models in accuracy

Abstract

Network Function Virtualization (NFV) is considered one of the key technologies for the 5G mobile networks. In NFV, network functions are implemented in software components denominated Virtual Network Functions (VNFs) running on commodity hardware. In this paper, we propose an analytical model based on an open queuing network of G/G/m queues to model VNFs with single- or multi-tier designs, and chains of VNFs. Our model is flexible and generic enough to capture the behavior of such systems. We validate our model by simulation. Specifically, we validate it for an LTE virtualized Mobility Management Entity with a three-tiered architecture use case. We also compare our model with the estate of the art, in terms of computational complexity and estimation error. The results show that our model has a computational complexity similar to the method for analyzing Jackson's networks. Additionally, our model exhibits an estimation error, measured as the relative error for the estimation of the mean response time, approximately equal to 10%, whereas for the considered baseline systems it ranges roughly from 60% to 90%.