15. Dynamic Control of Optical Networks

Significant developments in technologies such as distributed/cloud computing, mobile applications and the Internet of things () are driving demands for lower costs and higher throughput from the underlying network infrastructure. Optical networks have evolved accordingly (flex-grid, all-optical switching, etc.) to accommodate increasing demand and reduce capital expenditure (). In order to further lower costs, automation of control and management processes is essential to reduce human intervention over the service lifecycle. The need for automation has driven the development of optical control planes, which attempt to automate operations associated with provisioning and recovery from failures (service restoration). This chapter introduces the core functions involved in the control of optical networks, including network discovery, wavelength routing, dynamic service provisioning and seamless fault recovery. We chart the evolution from the inception of fully distributed control plane architectures to the more recent software-defined networking architectures and outline the already visible future trends in the dynamic control of optical networks, including intent-based networking and applications of artificial intelligence (AI).

This chapter is structured as follows. Section 15.1 introduces the background of optical control and management planes in legacy optical networks, and introduces control plane standards. Section 15.2 illustrates one of the first software-defined control and management plane artifacts, called path computation element (). Section 15.3 analyses the applications of software-defined networking () in optical networks. Section 15.4 presents some emerging trends in optical control planes, such as intent-based networking and applications of AI. Section 15.5 gives a summary and a few final remarks.