Software Networks

3Smart Edges

The first effect of the Cloud is to centralize the control and the orchestration system for the new generation of networks. Extreme solutions where there is only one center surrounded by radiating branches have been put forward as the solution of the future. For instance, we can cite the proposal of C-RAN (Cloud–Radio Access Network). However, many believe that centralizing everything is not the right solution, if only because of the problems of reliability and latency for real-time controls. The solution which actually comes into effect will undoubtedly need to be a compromise, with virtual machines situated at different points in the architecture. After explaining the different proposed architectural designs, we shall focus on intelligence in the extremities of the network, and thus what we call “smart edges”.

3.1. Placement of the controller

Figure 3.1 illustrates the different scenarios for the placement of the controller in a software network environment.

In Figure 3.1, we see three main scenarios. The first is highly centralized around an SDN controller. The control data are fed back automatically to that center. The second solution is to use intermediary machines at local or regional levels. These machines could be SBCs (Session Border Controllers) – a term which tends to be used in operator networks – or NACs (Network Access Controllers), corresponding to the solution favored by companies. In this scenario, the solution sends the control data to local or ...