Redesigning the Internet in "Clean slate approach" has attracted considerable attention. In clean slate approach, several network architectures are proposed, which are not based on the layered model. This paper discusses what model is appropriate to the network architecture for the New Generation Network from the viewpoint of ease of understanding, ease of management, and ease of implementation. As a result, this paper reaches a conclusion that the layered model with cross-layer collaboration and split of the data plane and the control plane is most appropriate. The major features of the proposed network architecture are as follows: (1) introducing the layer-5 to provide the applications with more abstract communication paths, (2) introducing cross-layer collaboration for efficient processing in each layer, (3) splitting the node identifier and the node locator for mobility, multi-homing, and security, (4) splitting the data plane and the control plane for manageability, and (5) introducing a recursive layered model to support network virtualization.