a Top-Down Approach (8th ed.):
Chapter 5 The Network Layer: Control Plane
5.1 Introduction
Per-router versus SDN control plane.
Two possible approaches for forwarding and flow tables are computed, maintained and installed:
• Per-router control (每路由器控制).
• A routing algorithm runs in each and every router; both a forwarding and a routing function are contained within each router.
• Logically centralized control (逻辑集中式控制).
• A logically centralized controller computes and distributes the forwarding tables to be used by each and every router.