Hardware choices for MPLS and backbone bridging

摘要

The traditional model of evolving hardware support for more complex routing in carrier-based network equipment assumed that smaller silicon features, more optimized design techniques, and stabilized high-layer protocols would converge to allow single-chip switch devices to climb up the protocol stack. Switches that once supported only Layer 1 PHY (physical) and Layer 2 data-link functions would grow over time to include Layer 3 network functions, Layer 4 transport duties, and a mix of higher-layer presentation and application functions to support duties such as deep-packet inspection. In a broad-brush approach, this vision still holds. The arri-