Open line systems present numerous benefits to operators and service providers. Organizations are no longer forced to buy all components of a networking solution from the same supplier. Today’s open line systems allow service providers to pick and choose between different options, ensuring that they have the best component from the best vendor for every part of the network. For instance, they could choose embedded optics from one vendor, transponders from a second and ROADM solutions from a third.
However, this openness comes with a potential challenge. A traditional approach with tightly boxed-in solutions made sure that all network components were sourced from the same vendor. This presented the one benefit that a single management solution could be used to manage the whole network as well as each individual network element. But how do you manage a disaggregated network that resembles a beautiful patchwork of best-of-breed solutions from a range of different vendors?
Smartoptics CTO Kent Lidström shares his view:
“Looking at the total life cycle cost of a communications network, operational and management expenses typically dominate the revenue calculation. Therefore, capable network management solutions are vital to making the communication network investment profitable and the business case attractive over time. As service providers move towards open, disaggregated networks, the question of management must be addressed. Rather than reverting to solutions that, on the one hand, simplify management through a common platform but on the other lock the user into one product brand, the answer again spells openness!”
Standardized data models and open APIs for integrated management
According to Kent, open management solutions could be addressed at three different levels. The first aspect comes down to how data about the individual network elements are stored and validated. YANG (short for Yet Another Next Generation) is a data modeling language defining how data can be sent over standard network management protocols. Kent explains:
“Most leading infrastructure providers are already supporting YANG, which was developed as a joint industry initiative. Because the software embedded on all network devices is both structured and validated according to the same standard, this means that it is not only easily accessible over open interfaces but also that it can be trusted.”
On the integration side, we are beginning to see how open APIs supporting documented standards such as NETCONF or REST API in all new network elements and devices make it possible to communicate with all elements in a similar manner. Standardized data models along with open APIs lay the foundation for both monitoring the state and automating configuration tasks for devices from different vendors in a consistent way.
Software-defined networking and open controllers
Another key development in the management of disaggregated networks is the use of open network controllers. Software-defined networking (SDN) has emerged as a modern approach to network management that provides the next layer for more flexible network monitoring and management. Kent explains:
“While traditional networks tend to be static and management of each element tied directly to a proprietary vendor solution, today’s increasingly dynamic networks require more flexible management. To enable this, the guiding principle of SDN is to centralize network intelligence to a control plane consisting of one or more network controllers. From a management point of view, the physical network elements can be considered ‘dumb’ and designed to be managed from this SDN ‘network brain’ where the whole intelligence is incorporated over standard protocols.”
As progressive equipment vendors join open-source communities, sign agreements such as the Open ROADM MSA with other likeminded vendors and adhere to standards like TransportPCE, interoperability becomes the norm. Along with this follows the capability to use open controllers to manage a wide range of different vendor solutions.
Orchestrators provide a user-friendly interface to manage networks
On the highest level in the open management framework, we can see how orchestrator software will provide the graphical user interface (GUI) that enables network operations to supervise and control the network. By communicating with each network element through the SDN and open control layer, equipment from multiple vendors can be managed at multiple layers in the network from the same user interface.
“The objective of Smartoptics is to develop an orchestrator supporting SDN and open controllers. The management solution will initially focus on all existing Smartoptics network elements but successively be developed to include support for all network elements supported by the open management approach,” Kent concludes.