Optical transport networks are benefiting from the availability of high-capacity and flexible line interfaces, universal optical transport network (OTN) switches, software-defined networking (SDN) controllers and real-time performance monitoring. Individually, each of these building blocks contributes to design and operate transport networks such that cost-effectiveness and robustness are improved. By leveraging their combined
capabilities, there is room for further enhancements. For instance, it is envisioned it will enable to adopt an optical channel provisioning strategy that relies on reduced performance margins, increasing the available
capacity per optical channel and potentially reducing capital expenditures (CapEx). This paper investigates this premise, describing a transport network architecture and a multi-layer optimization framework tailored for this
scenario. Network simulations obtained over two reference transport network topologies highlight that it enables to decrease the number of line interfaces and rerouting events.