Advantages of SDN
- The network is programmable and hence can easily be modified via the controller rather than individual switches.
- Switch hardware becomes cheaper since each switch only needs a data plane.
- Hardware is abstracted, hence applications can be written on top of the controller independent of the switch vendor.
- Provides better security since the controller can monitor traffic and deploy security policies. For example, if the controller detects suspicious activity in network traffic, it can reroute or drop the packets.
Software defined Networking(SDN)
SDN stands for Software Defined Network which is a networking architecture approach. It enables the control and management of the network using software applications. Through Software Defined Network (SDN) networking behavior of the entire network and its devices are programmed in a centrally controlled manner through software applications using open APIs.
To understand software-defined networks, we need to understand the various planes involved in networking.
- Data Plane
- Control Plane
Data plane: All the activities involving as well as resulting from data packets sent by the end-user belong to this plane. This includes:
- Forwarding of packets.
- Segmentation and reassembly of data.
- Replication of packets for multicasting.
Control plane: All activities necessary to perform data plane activities but do not involve end-user data packets belong to this plane. In other words, this is the brain of the network. The activities of the control plane include:
- Making routing tables.
- Setting packet handling policies.