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Figure 9. Routing/Switching Network Dichotomy
It becomes clear that two worlds emerge in the next-generation network architecture. One, switching-centric, is based upon the principles and attributes of the MSP. The other, routing-centric, is aimed at the public Internet service offering and is very much based on the principles and attributes of traditional, best-effort routers. These two worlds are converging, over time, into the next-generation network.
Figure 10. Switching and Routing Convergence
As shown in Figure 10, the competencies most attributed to switching solutions are end-to-end qualities of service, reliability, and ease of path management. The competency most attributed to routing solutions is reachability. The routing world has provided a network architecture whereby intelligence is distributed among many entities. Any-to-any connectivity is accomplished using a sophisticated control plane. The routing-centric world faces the challenge of delivering improved QoS and reliability to the internetworking domain—attributes fundamentally delivered via switching solutions. However, from a control-plane perspective, switching solutions very much have been transparent to routing solutions. This transparency must change in the near future to truly integrate the positive attributes of the switching world within a routing-centric network architecture.
The convergence of switching and routing will first take place in the network's core and the enabler for this true convergence is MSP.
