SDN (Software Defined Network) is the new buzzword in the networking space. We can say that a SDN network is nothing but a programmable and software based network technology that is defined and configured in such away that it aids in enhancing
SDN (Software Defined Network) is the new buzzword in the networking space. We can say that a SDN network is nothing but a programmable and software based network technology that is defined and configured in such away that it aids in enhancing the network efficiency. In this post we will dig deep into the various aspects of the SDN technology and also the protocols used in this Software Defined Network set up. So just relax and proceed further.
We will first start with revisiting some basic networking concepts that we have already covered in the previous posts. For understanding the SDN network concepts, it is important to recap the basics of OSI layers first for better understanding.
Note : If you are already well versed with the networking basics, then you may skip the next section and directly jump to the SDN topic down to the later sections.
What Is Networking? (Basic Definition Of Networking!!)
A network is basically defined as a link in between two or more devices (or people), that are linked to each other to exchange data and any kind of information. Once you understand what a network is, networking can be termed as the interaction with others (devices or people) to exchange information and develop professional or social contacts.
Now in a network there are various components present in it. Once a device transmit data, the data packets will pass through multiple layers of the network (OSI layers) before it gets received by the receiver device.
You may now wonder what exactly this OSI layer means?. Let us have a glimpse of the OSI layers in brief now :
Open Standard Interface (OSI) is a standard protocol that defines the communication between the two devices. The function of the OSI model is perfectly partitioned into seven distinct layers respectively. Let’s visit the seven layers.
Physical Layer : It is used to transmit the raw data over a communication channel. It transmits data as 0’s and 1’s.
Data Layer : Data is broken into frames, and the frames are transmitted sequentially. The primary use of this layer is to avoid transmission error.
Network Layer : Data is transformed in the form of packets. This layer routes the packet logically with the help of the IP address.
Transport Layer : This layer is responsible for end-to-end connectivity over a network. Here, the data is transformed in the form of segments.
Session Layer : This layer is responsible for establishing the session between the devices. This layer synchronizes the data between devices and establishes the connection between them.
Presentation Layer : This layer is responsible for formatting the data and provide proper encryption for the data.
Application Layer : This layer is used for transmitting and distributing the data between the devices.
Now let us understand some basic networking devices and their working :
Hub : Forwards the packet to every device that is connected to its network. It does not have an intelligence purpose. It is part of the physical layer (layer 1) of the OSI model. If you want to know more just click on this.
Switch : Used to receive the data and transfer them to the destination. The switch has an intelligence purpose. It forwards the packets based on the destination address. It is a part of data link layer (layer 2).
Router : Forwards the packet between the same or different network. It is a network layer device (layer 3). A router uses IP address.
Now let us see the various networking planes present in general :
Data Plane : Data plane is used to transfer the data between the devices. It deals with the entire processes involved in forwarding the packets from source to destination. It is also referred to as forwarding plane, user plane and carrier plane.
Control Plane : As the name suggests, it controls the movement of data. It deals with functions and processes that help determine the best path to transfer the data. Routing protocols are used in this plane to discover the devices on the network and understand network topology.
Management Plane : Its prime function is to control, monitor and manage the devices, and carry the administrative traffic. Protocols such as SNMP can be used for such operations.
Now it’s time to start exploring our main topic that is all about the Software Defined Network (SDN Network) technology in detail.
What Is Software Defined Network (SDN Technology)?
SDN work mainly on the Control and data plane (it separates both the planes). It employs the virtualization techniques in the networking space. SDN technology uses a smart controller to manage and monitor traffic through various Routers and switch combinations and further make the use of the dynamic routing of traffic efficiently.
The main idea behind SDN is to separate control and data plane and to make networks agile and flexible. SDN is a trend that is gaining importance with established vendors such as Brocade, Cisco, HP, and VMware.
SDN architecture is built using a combination of software and hardware that separates the SDN control plane and the SDN data plane of the network