Evolving SDN for Low-Power IoT Networks

Abstract

Software Defined Networking (SDN) offers a flexible and scalable architecture that abstracts decision making away from individual devices and provides a programmable network platform. Low-power wireless Internet of Things (IoT) networks, where multi-tenant and multi-application architectures require scalable and configurable solutions, are ideally placed to capitalize on this research. However, implementing a centralized SDN architecture within the constraints of a low-power wireless network faces considerable challenges. Not only is controller traffic subject to jitter due to unreliable links and network contention, but the overhead generated by SDN can severely affect the performance of other traffic. This paper addresses the challenge of bringing high-overhead SDN architecture to IEEE 802.15.4 networks. We explore how the traditional view of SDN needs to evolve in order to overcome the constraints of lowpower wireless networks, and discuss protocol and architectural optimizations necessary to reduce SDN control overhead -the main barrier to successful implementation. Additionally, we argue that interoperability with the existing protocol stack is necessary to provide a platform for controller discovery, and coexistence with legacy networks. We consequently introduce µSDN, a lightweight SDN framework for Contiki OS with both IPv6 and underlying routing protocol interoperability, as well as optimizing a number of elements within the SDN architecture to reduce control overhead to practical levels. We evaluate µSDN in terms of latency, energy, and packet delivery. Through this evaluation we show how the cost of SDN control overhead (both bootstrapping and management) can be reduced to a point where comparable performance and scalability is achieved against an IEEE 802.15.4-2012 RPL-based network. Additionally, we demonstrate µSDN 1 through simulation: providing a usecase where the SDN configurability can be used to provide Quality of Service (QoS) for critical network flows experiencing interference, and we achieve considerable reductions in delay and jitter in comparison to a scenario without SDN.

The Downside of Software-Defined Networking in Wireless Network

“…SDN is a well-defined approach and a promising solution for other networking areas. However, employing an SDN-based centralized architecture in the environment of a lowpower wireless IoT network introduces important challenges, such as the difficulty to control traffic, unreliability of links, network contention, and high associated overheads, which can significantly affect the performance of the network (Baddeley et al, 2018). This paper evaluates the overhead cost of SDN traffic network performance, delay, DER, and PDR.…”

“…It was installed on a Lenovo-IdeaPad-Y510P Laptop with an Intel Core i7-4700MQ processor with 7.7 gigabytes of random access memory. In this environment, it was unnecessary to install the Contiki platform because it was included as part of the µSDN (Baddeley et al, 2018), a low overhead SDN stack, and embedded in the SDN controller for Contiki OS. However, it was necessary to install compilers such as the 20-bit mspgcc compiler (20bit) and the precompiled MSP430-GCC version 4.7.3 (msp430).…”

“…An SDN standard for low-power wireless networks called µSDN (Baddeley et al, 2018) was used for simulation in this study. µSDN is a lightweight SDN architecture for Contiki OS, which supports both IPv6 and interoperability with distributed routing protocols such as RPL, as well as optimizes the combination of a number of overhead reduction functions to enhance the scalability and mitigate the cost of the SDN within a low-power IoT environment.…”

Intent‐based service management for heterogeneous software‐defined infrastructure domains

“…[28][29][30] From the network management viewpoint, SDN may enable traffic control and load balancing. As an example, in Baddeley et al, 31 it is shown that the SDN controller may steer traffic in noninterfered area, improving network performance. When it comes to resource utilization, the SDN approach allows viewing nodes as resource providers and to efficiently map the users' requests into the proper resources.…”

“…However, no resource management or QoS‐based network management is considered. An extension of the 6LoWPAN protocols stack was proposed to implement SDN, demonstrating performance improvement with respect to the Routing Protocol for Low Power and Lossy Networks (RPL)–based decentralized solution. Results are obtained via a platform emulating TI CC2420 devices and not using real devices as we do in our paper.…”