On The Modeling of OpenFlow-based SDNs: The Single Node Case

TL;DR

This paper introduces a refined model for OpenFlow-based SDNs that accurately predicts network performance even with high flow arrival rates and can be extended to multiple nodes, improving upon previous models.

Contribution

It presents a new Jackson-based model tailored for OpenFlow SDNs that overcomes previous limitations regarding flow probability and multi-node extension.

Findings

Model remains accurate with high flow probabilities

Extension to multiple nodes demonstrated with a toy example

Improved understanding of SDN performance under various conditions

Abstract

OpenFlow is one of the most commonly used protocols for communication between the controller and the forwarding element in a software defined network (SDN). A model based on M/M/1 queues is proposed in [1] to capture the communication between the forwarding element and the controller. Albeit the model provides useful insight, it is accurate only for the case when the probability of expecting a new flow is small. Secondly, it is not straight forward to extend the model in [1] to more than one forwarding element in the data plane. In this work we propose a model which addresses both these challenges. The model is based on Jackson assumption but with corrections tailored to the OpenFlow based SDN network. Performance analysis using the proposed model indicates that the model is accurate even for the case when the probability of new flow is quite large. Further we show by a toy example that the model can be extended to more than one node in the data plane.