Separation of control and forwarding plane inside a network element
R. Gopel L · 2003
Routers in Internet plays an important role in transporting Internet protocol (IP) packets. Quality of service (QoS) aware router, policy based routing and middle-box functions such as firewall, network address translation (NAT), proxies etc put heavy requirements on per-hop behavior treatment for IP packets. Apart from this the convergence of telecom, wireless and Internet will likely to drive different new services which may demand more per-hop behaviour treatment on routers. To keep pace with this demanding requirements, routers have emerged from simple monolithic software to a distributed routing complex that interconnects different networks and distributes the routing and forwarding logic to line cards and control cards. Even though such a distributed processing has made the routing element modular, but still the communication between control and line cards are propriety and does not ease the operation of control and management on the routers. We describe the need for separation of control and forwarding plane then we define the forwarding element (FE) model and explain how this can be transported between line card and control card inside a network element using forwarding and control element protocol (FACT).