What is Open Flow Protocol Networking and How it Works?

This article talks about the open flow protocol, its basics, and the advantages it offers in the current network environment. 

Introduction:

In this post, we will learn the fundamentals of the OpenFlow protocol, which is right now the industry standard in traditional software-defined networks termed SDN networks. This type of network is a generic idea that separates the network's forwarding plane and control plane. It is the most general phrase, which includes Open Flow, Controllers, Network Devices, and so on.

What is Open Flow Protocol?

So, Open Flow is the protocol used in SDN to communicate between the network's forwarding plane and control plane. In other words, Open Flow is used for communication between the controller and the network devices by enabling network device operations and management using the Open Flow Interface. It is a common control plane standard used in SDN operations, allowing it to communicate with other SDN solutions. This is a Layer 2 communication protocol that is utilized in SDN between the controller and a network switch. 

The Open Networking Foundation (ONF) defined it as a multivendor standard for deploying SDN in networking equipment. The OpenFlow protocol allows the OpenFlow Controller to direct how the OpenFlow switch handles incoming data packets. "Flows" are the OpenFlow instructions sent from an OpenFlow Controller to an OpenFlow switch. Each flow is made up of packet match fields, flow priority, various counters, packet processing instructions, flow timeouts, and a cookie. Tables are used to organize the flows. Before exiting an egress port, an incoming packet may be handled by flows in numerous "pipelined" tables. 

This protocol provides access to the network devices' Forwarding Plane. The distinction is that OpenFlow is the only control plane in the switch, and it survives power cycles, and all flows and redundancies are proactively traffic-engineered so that the switches may accomplish the forwarding they are set to do with or without telephony. Such kind of networks are designed to decouple network control and forwarding processes. This allows network control to be directly programmable and the underlying infrastructure to be separate from applications and network services.

This should be noticed that the Open Flow protocol has no impact on the rest of the network. A packet capture between two switches in a network that are both connected to the controller via another port would not reveal any of the messages between the switches. It is only intended for use between a switch and a controller. The remainder of the network is unaffected. 

A real-world OpenFlow capable network could be made up entirely of OpenFlow switches or a combination of OpenFlow switches and traditional switches and routers. An overlay network is the latter sort of network. Some OpenFlow applications will only require a partial deployment of OpenFlow switches, but others would require an entirely OpenFlow-based network. 

Impact of Open Flow Protocol:

OpenFlow and SDN have various advantages over traditional networks as well. There are many direct advantages of this protocol in networks. SDN allows for the separation of the control and data planes, switches can dedicate all of their hardware resources to forwarding data rather than computing routes. It also proves itself to be a simple method of communication between the controller and switch that may be readily deployed in an existing network. Most modern devices support OpenFlow; it is not activated by default, but it is simple to enable and utilize for SDN transition. This protocol also protects the controller and/or the network by using a TLS connection to avoid spying and DoS threats.

Conclusion:

We can conclude by stating that packet forwarding and high-level routing occur on the same device in a traditional switch but the data path is separated from the control path by an OpenFlow switch. The Open Flow protocol is used to communicate between the switch and the controller. The data path part is located on the switch itself; high-level routing decisions are made by a separate controller. This technology, known as software-defined networking enables more efficient use of network resources than traditional networks allow. OpenFlow has gained popularity in applications such as mission-critical networks, and next-generation IP-based mobile networks and is expanding its role in modern technology.