| The sudden growth of Internet has exposed some of the problems with its architecture: forwarding performance, traffic engineering, and quality of service. We address these issues through the concept of a Virtual Network Port (VNP), which enables bypassing of the network layer, identifying traffic remote network interfaces. We have applied this simple concept to implement layer-3 switching. A VNP provides a conduit below layer-3 to remote nodes and networks. Traffic through a VNP can be shaped, policed, encrypted etc.; a VNP's control procedure provides for generic packet processing. VNP paths are setup implicitly by routing protocols, or explicitly based on QoS constraints. VNP domains are arranged in a hierarchy to provide scalability at the core of an internetwork. We compare VNP with Multi-Protocol Label Switching (MPLS) quantitatively using simulation. Packets through a VNP across multiple networks do not require fragmentation. VNP framework is conceptually simpler, has better semantics, and is more efficient than MPLS. VNP has applications in other domains as well; we describe the design of a scalable IP router using VNP. |
