In the OSI model.what is the primary function of the Network layer? The primary function of the Network layer is to encode and convert data into signals sultable for transmission over the physical medium. The primary function of the Network layer is to move data around an internetwork using logical network and host IDs. The primary function of the Network layer is to establish, manage, and terminate connections between applications on different hosts. The primary function of the Network layer is to ensure reliable transmission of data across a physical link.