Controller Placement for minimum control traffic in opendaylight clustering

Abstract

Software-defined networking (SDN) decouples the control and data planes and moves the control logic to the SDN controllers. The controllers are servers handling the switches and directing their traffic with the use of open and non-proprietary protocols. Consequently, the controller is crucial for the network performance. OpenDaylight (ODL) is a widely recognised controller platform implementing a clustering mechanism, where multiple controllers are synchronized to behave as a single one, while also enabling load balancing and failure resilience. The purpose of this paper is to extract the communication patterns between the ODL controllers in a cluster, as well as between the controllers and the switches, in order to place the cluster controllers appropriately in a network. Our testbed experimentation reveals the bandwidth requirements of the control traffic in an ODL cluster, while a network model is introduced for the problem of determining the optimal controller placement for minimum control traffic. © 2019 IEEE.