Efficient topology discovery in software defined networks

Abstract

Software Defined Networking (SDN) is a new networking paradigm, with a great potential to increase network efficiency, ease the complexity of network control and management, and accelerate the rate of technology innovation. One of the core concepts of SDN is the separation of the network's control and data plane. The intelligence and the control of the network operation and management, such as routing, is removed from the forwarding elements (switches) and is concentrated in a logically centralised component, i.e. the SDN controller. In order for the controller to configure and manage the network, it needs to have up-to-date information about the state of the network, in particular its topology. Consequently, topology discovery is a critical component of any Software Defined Network architecture. In this paper, we evaluate the cost and overhead of the de facto standard approach to topology discovery currently implemented by the major SDN controller frameworks, and propose simple and practical modifications which achieve a significantly improved efficiency and reduced control overhead. We have implemented our new topology discovery approach on the widely used POX controller platform, and have evaluated it for a range of network topologies via experiments using the Mininet network emulator. Our results show that our proposed modifications achieve an up to 45% reduction in controller load compared to the current state-of-the-art approach, while delivering identical discovery functionality.

Efficient topology discovery in OpenFlow-based Software Defined Networks

“…We present experimental results which demonstrate this. The work presented in this paper is an extension of previously published initial and preliminary work by the same authors [17].…”

Discovering the Network Topology: An Efficient Approach for SDN

“…Moreover, they have proposed simple and practical modifications to reduce the controller overhead during the topology discovery procedure. In (Pakzad et al, 2014), after implementing the improved approach in POX controller and Mininet emulator, results show a reduction in the controller overload up to 45%. On the other hand, testing the proposed modification in a specific topology in OFELIA SDN testbed (Pakzad et al, 2016), show a reduction in the controller overload up to 40%, while the physical topology is showed in the same fashion.…”

“…Efficient procedures for topology discovery in SDN have been already researched in (Pakzad et al, 2014;Pakzad et al, 2016). The topology discovery mechanisms proposed by the authors have focused on improving the current OpenFlow-based SDN mechanism.…”

“…The authors of (Pakzad et al, 2014;Pakzad et al, 2016) evaluate the efficiency of the current OFDP mechanism implemented by major SDN controllers. Moreover, they have proposed simple and practical modifications to reduce the controller overhead during the topology discovery procedure.…”

Security in software defined networks

“…While there is no official standard for an SDN topology discovery mechanism, there is a defacto standard, which is sometimes informally referred to as Open Flow Discovery Protocol (OFDP) [117,118]. All major SDN controllers implement it in essentially the same way, most likely due to the fact that it has been adopted from NOX, the original SDN controller [48].…”