Architectures with Shared‐Memory‐Based Switch Fabrics: Case Study—Cisco Catalyst 8500 CSR Series

The Catalyst 8500 campus switch/routers (CSRs) provide wire speed Layer 2 and Layer 3 packet forwarding and services. Based on architecture categories, the architectures of Catalyst 8500 CSRs fall under "architectures with shared‐memory‐based switch fabrics and distributed forwarding engines" This chapter discusses the main architectural features of the Catalyst 8500 series. The Catalyst 8500 CSR has a distributed forwarding architecture where all line cards in the system can forward packets locally. The system processor (SRP or RP) ensures that the Layer 2 and Layer 3 forwarding information in the line cards are up‐to‐date. The Catalyst 8500 supports a distributed forwarding architecture that uses a forwarding approach where the forwarding information generated by the central system processor is distributed to the individual line card modules to enable them forward packets locally. It also supports a number of quality of service (QoS) mechanisms that are incorporated into the switch/router architecture.