Implementation of IP forwarding engine for ATM-based MPLS LER system

We introduce the architecture of a multiprotocol label switching (MPLS) label edge router (LER) system based on the ACE2000 ATM switching system. We implemented the MPLS LER system by adding the MPLS service controller and MPLS interface module (MIM) with 2.5 Gbit/s throughput to the ACE2000 ATM switching system. We also describe the implementation of the MIM that can support ships-in-the-night mode such as ATM service and Internet service in the MPLS LER system. We designed the MIM to have a high-performance IP router function as well as ATM processing functions. It consists of a physical layer processing part, IP forwarding engine and VC merging part, ATM layer processing part, and switch interface part. The most important part of this module is IP forwarding engine, because it has a major effect on the performance of the MPLS LER system. We propose a high-performance IP forwarding engine that can support QoS-based multi-services such as ATM service, MPLS VPN service, emulated leased line (ELL) service, and real-time (RT) service, as well as best-effort service. It provides a high-speed IP lookup by a hardware-based pipelined and parallel lookup control scheme and CAM-based IP search engine. It provides 622 Mbit/s wire-rate forwarding performance and 14 Mpps lookup performance.