In order to effectively enhance the abilities of computer networks, these issues need to be addressed urgently. Therefore, we propose a clear separation of packet forwarding, control and management. We advocate the 3N architecture, by introducing the discrete forwarding network, control network, and management network to provide these three kinds of functions respectively. The control network performs the global decisionmaking based on the global state of the forwarding network to achieve the overall optimal control. The forwarding network mainly forwards user packets by using simplified forwarding device to improve forwarding efficiency. The management network mainly configures and monitors the forwarding network behavior and content to achieve the overall network performance measurement and evaluation. The forwarding network, control network, management network effectively interact together to constitute an organic computer network system. Although the 3N architecture is still facing many challenges by far now, we think that the 3N architecture is helpful to improve network security, availability, manageability, scalability and so on. It is helpful to the development of future networks and has a far-reaching impact on continuing technological innovation.