OLC: Open-Level Control Plane Architecture for Providing Better Scalability in an SDN Network

The Internet has changed the world, regarding how we lead our daily lives and in recent years, with new technologies, such as the Internet of Things and wireless sensor networks escalating this change. However, these technologies bring with them a rapid increase in traffic, thereby putting more load on networks. It is hard to extend the traditional fully distributed architecture and distributed aggregation mechanism to a large scale, because they suffer several drawbacks by using the data plane as a bus to transfer the control discovery messages, which increases the traffic on that plane. Consequently, to solve this issue, a general architecture and discovery mechanism are introduced in this paper with open-level control (OLC) plane architecture, thus providing better scalability in an software defined networking (SDN) network. Regarding OLC, the backbone for different domains and the discovery process for providing a network general view are considered. OLC can scale up the network with high performance even during high traffic. In particular, it has high transparency, with there being no need to change the hardware, software, or protocols on the host side. Finally, the results from a 22 PC testbed verify that OLC offers a reduction in the number of discovery packets in the data plane of 84.2%, 55.2% faster discovery time and scaling up the number of subnets in an SDN network 3.2 times more than with the traditional distributed architecture and mechanism. Moreover, it provides an approximately steady rediscovery time of 4.34 sees even with very high load.