This paper investigates the important area of lightpath provisioning in multi-domain full wavelength conversion DWDM networks. Although inter-domain provisioning has been well-studied for packet/cell-switching networks, the wavelength dimension (along with wavelength conversion) poses many challenges. To address these concerns, a detailed GMPLS-based hierarchical OSPF-TE routing framework is developed to facilitate inter-domain lightpath provisioning. Namely inter-domain OSPF-TE routing is used to adapt topology abstraction to hide internal domain state so as to resolve routing scalability and security issues. Specifically a novel full-mesh topology abstraction scheme is developed for full wavelength conversion domains, i.e., to disseminate additional wavelength converter state. Related inter-domain lightpath RWA and signaling schemes are also tabled. Performance analysis results are then presented to demonstrate the effectiveness of the proposed mechanisms.