Edge Networking

3Fog Networks

Fog Computing is also called Edge Computing in a more general framework regrouping the level above (the MEC) and the level below (the Skin). This is a model in which data, computation and storage are concentrated at the edge of the network, in the company, rather than in major cloud providers. The term Fog Computing was introduced by Cisco in 2013 to define this new model allowing objects to connect to edge equipment and be processed at that level before sending the processed data to a cloud data center.

3.1. Fog architectures

Before breaking the Cloud architecture into four main levels (Cloud, MEC, Fog and Skin), it was first highly centralized around large but remote data centers, then decomposed into two levels, Cloud and Fog, as illustrated in Figure 3.1.

In this context, the Fog covers everything that is located on the ends of the network from the edge router, whether it is on the operator side or the enterprise side. If it is on the enterprise side, it is called an enterprise controller. If it is on the operator side, it is called a session border controller (SBC), which today has greater functionalities than those initially defined to secure VoIP and play the role of a SIP firewall.

The word Fog can sometimes be used for small data centers, which we will come back to in Chapter 6 as Skin data centers, where the users are within Wi-Fi or femtocell range of the data center. This case is illustrated in Figure 3.2.

Figure 3.1. The object-related architecture ...