OpenFlow is a technological standard for the administration of computer networks. OpenFlow was designed by academic researchers with the goal of making the behavior of network routers, network switches, and other access points programmable, and companies in the industry have been adopting this technology for business applications.
What OpenFlow does
OpenFlow allows administrators to centrally control how routers and switches manage their data routing decisions. While in traditional networks each device is configured by an administrator with the necessary policies, in an OpenFlow-enabled network, policies are programmed across all switches and routers as a group… Policies can be changed and devices can be reprogrammed through the same interfaces.
In academic settings, OpenFlow is used to experimenting with custom network routing protocols. In data centers, OpenFlow can help greatly simplify the management of virtual servers and similar back-end applications.
How Open Flow works
OpenFlow establishes a central service device on the network as the OpenFlow Controller . This driver establishes connections to OpenFlow-aware routers and switches and sends commands to them over a specific network protocol (typically running over TCP/IP). These commands tell receiving devices to update their logic (sometimes called forwarding tables) to process packets. Routers and switches can also send messages (primarily error notifications) to the controller in return.
Problems with OpenFlow
Routers and switches must implement OpenFlow protocol logic to be controllable. A company that has deployed large amounts of legacy hardware must spend significant effort and expense to upgrade their environment to work with the protocol.
The concept of programmable devices is new to many administrators. Training and certification programs for OpenFlow are much less mature than those for traditional networking technologies. Companies can struggle to find the right talent to help them adopt OpenFlow.
There are alternative approaches to Software Defined Networking alongside OpenFlow. With the rapid evolution of the industry, it is possible that a new standard will emerge that will quickly replace OpenFlow and limit the return on investment a business can achieve by adopting it.
