A Comprehensive Study on Load Balancers for VNF chains Horizontal Scaling

TL;DR

This paper introduces an architecture and implementation for horizontal scaling of virtual network function chains that maintains state and traffic consistency without modifying network functions, using connection-aware load balancing.

Contribution

It presents a novel load balancing approach for stateful VNF chains that requires no changes to network functions and supports dynamic scaling.

Findings

Feasibility demonstrated through extensive simulations

Effective load distribution across VNF instances

Maintains state consistency during scaling

Abstract

We present an architectural design and a reference implementation for horizontal scaling of virtual network function chains. Our solution does not require any changes to network functions and is able to handle stateful network functions for which states may depend on both directions of the traffic. We use connection-aware traffic load balancers based on hashing function to maintain mappings between connections and the dynamically changing network function chains. Our references implementation uses OpenFlow switches to route traffic to the assigned network function instances according to the load balancer decisions. We conducted extensive simulations to test the feasibility of the architecture and evaluate the performance of our implementation.