Planes in Networking

Type of Planes in Networking

Conventionally speaking, we have three planes in any network device (routers, switches, etc.) viz.

1. Control Plane,
2. Data Plane, and
3. Management Plane

But, there exists one more plane, that is, Service Plane. The reason, why you won't find this plane mentioned in your textbooks, is because the term Service plane was officially coined very recently. We will discuss about this later in the section below. First, let's get started with the three conventional planes.

Control plane and Data plane:

Let's say you have three PCs (A, B, and C) connected over a switch(S) at your home and you want to send some bits/bytes of data (also called payload) from A to B. So this data (or payload) will be in the Data Plane of the switch S. 

Now, the switch S has to direct the packet, which contains the payload, to the port on which B is connected. To achieve this delivery of the packet, the switch S generates some bytes of data which control the journey of the packet from source (A) to the destination (B). These bytes of data are in the Control plane of the switch S.

In today's existing Network infrastructures, the Control plane and the Data plane are very much inter-twined. So, if you disguise yourself to be the control bits for a network device, you can route the payload(user's private information) towards you.

In SDN (Software Defined Networking), the Control and the Data planes are separated, which provides a whole new perspective towards the future Network infrastructures where SDN will be implemented.

Management Plane:

There are two types of extra bits (i.e. the bits apart from your payload) over your network. One, we already talked about: the control bits and the other one is management bit.

Let's say if we ask the switch S: how many messages are sent? The switch S will reply, say, 50 bits were sent. The bits of data generated by these sort of questions fall under Management bits and ultimately under Management plane.

This plane is basically responsible for accounting, keeping track of events, etc. Even if this plane doesn't exist, the packet flow over our network will be just fine.

Note: Though the control and the data planes are inter-twined together, but the Management plane is  always separated.

Service Plane:

This includes all the services available in our network. e.g. Firewalls, Intrusion Detection, SSL, Load Balancers, etc.

Hope this helped you clear your doubts. If you want to discuss anything related to networking, feel free to drop your valuable suggestions in the comments below and I'll get back to you asap!