On October 26th I attended the OpenFlow Symposium in San Jose, CA hosted by Packet Pushers and TechFieldDay at the DoubleTree San Jose. The purpose of this symposium was to help gain more exposure to OpenFlow as well as discuss what some of the major players see and feel about the technology. In attendance was representatives from Big Switch Networks, Brocade, Cisco, Google, Juniper, NEC, and Yahoo!. They each were allowed to present their views and feelings and then the panel was opened up for discussion and questions.
My take was that Google and Yahoo! are big into this technology as they have the most to gain from it.  They run warehouse size data centers all over the world, and this type of technology has a huge benefit to them as it means they can develop their own controllers and control merchant silicon, thus releasing them from relying on other vendors network hardware to support their data center. Not only that, but they can help prioritize and track individual flows based on what the user is doing. For example – a person who is placing items in their carts and heading to checkout can have a higher priority flow over someone just looking around.  The speed to finish the transaction is important to them, not to mention they can also secure that traffic in the network differently then a person who is just looking.

An OpenFlow Symposium was held in San Jose, CA on October 26th, 2011 and hosted by by PacketPushers.Net and TechFieldDay.Com. This was my first true exposure to the OpenFlow protocol and concepts of SDN (Software Designed Networking), and it was a great exposure.
If you are not familiar with OpenFlow or SDN, please let me take a moment and give you a brief overview and a quick scenario. OpenFlow is a way in which you can have a application – called a Controller – maintain and control switch flow tables. This controller is aware of all flows in the topology of its domain, the domain being the switches/ports that it controls. Yes, you can have specific ports on a switch controlled via the controller, and all the other ports as part of a normal network that is controlled via the switch. OpenFlow will have no impact to the other ports, they will continue to operate just like nothing was different.
A good use case for OpenFlow is Multi-Path Layer 2 switching in a data center or other high bandwidth location. With normal multi-patch technologies one of the links is blocked via STP, thus sitting idle just waiting for the primary link to fail. With OpenFlow, the controller is aware of all paths in the network and able to load the traffic accordingly. Lets take a look at the following diagram: