The class of Open Optical Networks (OON) aims to describe the peculiarities of data networking based on the exploitation of photonic transmission over optical fiber networks. The specific focus is on multilayer optimization below the IP layer, enabling full exploitation of the photonic transport layer using either state-of-the-art WDM fixed-grid or the already standardized flex-grid. Network analysis will rely on the progressive abstraction of network elements and subsystems within the network digital twin, enabling open network management based on common APIs and data structures. The teaching method will follow an application-oriented introduction of concepts. To this end, students will be required to develop Python modules performing simple network control operations, potentially utilizing the open-source library GNPy from the Telecom Infra Project. These assignments will follow a progressive approach to build a "toy" network digital twin and test the control and loading network procedures. Coding will adhere to standard open-source procedures based on GitHub. Lectures on Python coding and the use of GitHub will be included in the class. Furthermore, the quantum communications on optical fiber networks will be introduced. Seminars will tentatively be given by companies and operators in the field. In particular, seminars may be provided by representatives from Meta, Cisco, SMOptics, Infinera, Nokia, GARR, OpenFiber, and TIM. The final student assessment will be based on the discussion of the assigned homework. For OON students, a set of homework assignments will be available that may evolve into a Master’s thesis, serving as its initial phase. The OON class will leverage the experience gained from participating in the Telecom Infra Project consortium. Theoretical lectures will be integrated with exercises performed as virtual laboratories, as described below. NOTE: Both theoretical lectures and practical software exercises are fully compatible with remote online teaching.