An End-to-end Performance Analysis for Service Chaining in a Virtualized Network
06 January 2020
Future mobile networks supporting Internet of Things are expected to provide both high throughput and low latency to user-specific services. One way to overcome this challenge is to adopt network function virtualization and Multi-access edge computing (MEC). Besides latency constraints, these services may have strict function chaining requirements. In other words, each service has to be processed by a set of network functions (e.g., firewalls, transcoders, load balancers, etc.) in a specific order. Furthermore, the requirements of 5G networks for flexibility and elasticity of the network inspire the idea of Network Function Virtualization (NFV). In this paper, as a first step, we analyze a simple end-to-end communication system that consists of both MEC servers and a server at the core network hosting different types of virtual network functions. We develop a queueing model for the performance analysis of the system consisting of both processing and transmission flows. The system is decomposed into subsystems which are independently analyzed in order to approximate the behaviour of the original system. We provide approximate analytical expressions of the performance metrics such as system drop rate, end-to-end delay, and system throughput. Based on the first step, we provide a stochastic model for larger systems with arbitrary number of servers at the edge. Simulation results show that our approximation performs quite well. By evaluating the system under different scenarios, we provide insights for the decision making on traffic flow control and its impact on critical performance metrics.
