Core networks of the future will have a translucent and eventually transparent optical structure. Ultra-high-speed end-to-end connectiv- ity with high quality of service and high reliability will be realized through the exploitation of opti- mized protocols and lightpath routing algorithms. These algorithms will complement a flexible con- trol and management plane integrated in the proposed solution. Physical layer impairments and optical performance are monitored and incorporated in impairment-aware lightpath rout- ing algorithms. These algorithms will be integrat- ed into a novel dynamic network planning tool that will consider dynamic traffic characteristics, a reconfigurable optical layer, and varying physi- cal impairment and component characteristics. The network planning tool along with extended control planes will make it possible to realize the vision of optical transparency. This article pre- sents a novel framework that addresses dynamic cross-layer network planning and optimization while considering the development of a future transport network infrastructure.