Part of the Routing and switching glossary:

OpenFlow is a protocol that allows a server to tell network switches where to send packets. In a conventional network, each switch has proprietary software that tells it what to do. With OpenFlow, the packet-moving decisions are centralized, so that the network can be programmed independently of the individual switches and data center gear.

In a conventional switch, packet forwarding (the data path) and high-level routing (the control path) occur on the same device. An OpenFlow switch separates the data path from the control path. The data path portion resides on the switch itself; a separate controller makes high-level routing decisions. The switch and controller communicate by means of the OpenFlow protocol. This methodology, known as software-defined networking (SDN), allows for more effective use of network resources than is possible with traditional networks. OpenFlow has gained favor in applications such as VM (virtual machine) mobility, mission-critical networks, and next generation IP-based mobile networks.

Several established companies including IBM, Google, and HP have either fully utilized, or announced their intention to support, the OpenFlow standard. Big Switch Networks, an SDN firm headquartered in Palo Alto, California, has implemented OpenFlow networks that run on top of traditional networks, making it possible to place virtual machines anywhere in a data center to reclaim stranded computing capacity. By early 2012, Google's internal network ran entirely on OpenFlow.

This was last updated in June 2012
Contributor(s): Stan Gibilisco
Posted by: Margaret Rouse

Related Terms

Definitions

Glossaries

  • Routing and switching

    - Terms related to routers and switches, including definitions about hubs and words and phrases about packet-switched networks.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question. Find an Answer.Powered by ITKnowledgeExchange.com

Ask An IT Question

Get answers from your peers on your most technical challenges

Ask Question

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.