How SDN Technology Works?

Software-defined networking (SDN) is a network architecture that uses software to control and manage the flow of data across a network. It is designed to make networks more agile, flexible, and programmable. SDN works by separating the control plane from the data plane, allowing the network to be managed and programmed independently of the underlying hardware. This separation of control and data planes allows for more efficient use of network resources, faster response times, and better scalability. SDN also enables network.

The question is how the SDN technology works. Moving to this topic first, we previously mentioned (How does a router work?) that when sending data in the network, this data reaches different network devices such as a Switch and a Router. Each device handles this data in a specific way and has specific operations that cannot be delivered to its destination, such as packaging processes Encapsulation, De-encapsulation, and encryption... Etc.

How SDN Technology Works?

Network devices use tables in which they record important information that they use to perform their task to pass data in a certain direction and determine the interface port to use to send data. For example, the Switch device uses a table called the address table (Physical MAC Address Table), Router uses a table called Routing Table or Scroll Table, and each device creates, monitors, and adjusts these tables as needed by using specific protocols such as STP, ESPF, and RIP protocols... Etc.

We use the CLI command line interface to adjust, set up the device and control its properties and operation mode. And the CLI Interface is accessible with a Console port, Telnet or SSH protocol or SNMP protocol can also be used.

Therefore, we can categorize and divide the operations done in network devices into three levels.

Level 1:

The Level of operations done on the Data Plane (such as Encapsulation and Unpackaging De-Encapsulation data).

Level 2:

The level of Control Plane control operations (as creating the MAC Address Table), and Routing Table using an appropriate protocol such as OSPF or RIP to control sending data to a specific path).

Level 3:

Management Plane operations level (as tuning and modifying the device using the Console port, Telnet, SSH, or SNMP protocol).

We observe in traditional networks, that each device of the network devices executes these three levels of operations individually, that is, in each device, Data Plane level operations are implemented, and Control level operations are carried out, Control Plane implementation, Management level operations M Plane management.

Traditional Networks Working

For example, if we want to set RIP protocol in our network to create the orientation table, Routing Table (Control Plane), enter the CLI command line interface of each device and use the appropriate commands (i.e. implementation Management Plane). So when data arrives at the device it can use the routing table for passing data to its destination (i.e. implementing data level operations (Plane Data).

With advances in networks science, modern technology has emerged that simplifies network management and makes adjustments to it especially when the network contains a large number of network devices, and this technology depends on the design of the network so that through a central device, these devices are controlled, someone is implementing level control operations (Control Plane), Like performing the Dynamic Routing Protocols functions and gathering the necessary information and helping devices register this information to them, and this device is called a "Controller".

Controller working

Other Network Devices will implement Data Planes data levels operations such as Encapsulation and De-Encapsulation removal.

The Controller is tuned and set up to perform its tasks using special Applications that implement management-level operations Management Plane.

This technology is called Software Defined Networking SDN and is also called:

v Network Programmability

v Controller-based networking

v Network Automation.

This technology will change the way we deal with networks, opening up vast areas for their development, reducing human interference in preparation and management processes, and even according to different and changing circumstances, it allows room for AI intervention to choose the best ways of working the network. Developing new applications that meet medicine, will also open wide opportunities. The increasing use of modern technology in many aspects of our daily lives is without exception.