IP forwarding engine with VC merging in ATM-based MPLS system

In this paper, we describe the necessity of VC merging in an edge label switched router (LSR) for scalability, one of the important merits in multi-protocol label switching (MPLS). We introduce the design of a high-speed IP forwarding engine with virtual connection (VC) merging. This forwarding engine largely consists of a segmentation and reassembly (SAR) processing part, a CAM-based IP look-up processing part, a VC-merging part, and a physical line interface part. It provides some desirable characteristics that are described in this paper. We also compare the edge MPLS systems with centralized and distributed forwarding engine architectures, and the good points of the MPLS system with the latter architectures when supporting VC merging