A unified API is provided to an optical networking apparatus to facilitate uniform access, control or interaction with its multi-protocol optical networking modules (MPONM) by its applications. Each of the MPONM has a multi-protocol processor with a number of function blocks and physical layer components. Corresponding service routines are provided for the function blocks and the physical layer. Functions of the function block/physical layer service routines are externalized through the same unified API, thereby enabling accesses and interactions with physical layer components of a MPONM to be conducted in the same high level manner as accesses and interactions with function blocks of the multi-protocol processor of the MPONM.