Components of traditional networks
Let us start our deep dive into SDN by looking at the components of a network device. Networking functionality can be broadly classified into three planes. These are as follows:
Data plane: The act of moving bits that constitute the packet from an incoming port to an outgoing port is the responsibility of the data plane. This is also known as the forwarding plane. For example, in Ethernet switches, packets coming in from one port are forwarded out via one or more of the remaining ports.
Control plane: Using the previous example, to forward the packet to the correct outgoing port, the data plane may need additional information. In the case of Ethernet switches, the outgoing port is identified using the destination MAC address learnt by the switch. This act of learning and building awareness about the network is the responsibility of the control plane. The control plane learns and gathers information about the network using various protocols. In a switch...
