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OpenFlow/Specifications

Who Does What: SDN Controllers

The controller is the logical control center of the SDN network, communicating with switches via its "southbound" interface to provide networking instructions and communicating with applications via its "northbound" interface.

In SDN's purest form, the controller has all the intelligence: Switches are dumb, commercial off-the-shelf (COTS) devices that are managed by the controllers.

Operators that find this pure approach too rigorous can instead opt for an overlay, espoused by Cisco Systems Inc. (Nasdaq: CSCO), VMware Inc. (NYSE: VMW) and other vendors. In the overlay approach, the SDN network runs as a software layer on top of existing networks. Switches can be either COTS or proprietary.

SDN controller deployments are mostly to be found in data centers currently, but they have also been deployed in wide area enterprise networks and are creeping into wide area service provider networks too as carrier-class capabilities come to market and business cases are identified.

SDN, in theory, allows networks to be programmable, flexible and cheaper to run. It's foundational to the New IP -- the transformation of carrier networks from cost centers to revenue drivers delivering value to customers. (See Introducing 'The New IP' .)

Light Reading took a quick look at the SDN controller marketplace and compiled a list of vendors and open source organizations that are offering, or have developed, SDN controllers or the code that can be used to develop one (in the case of the open source community).

The list is split into two: vendors with commercial products; and the open source projects/organizations that are engaging the wider community to develop SDN controller software. Many of the commercial vendor controllers are based on open source code, particularly that developed by OpenDaylight , a collaborative project set up by the Linux Foundation .

Brocade Communications Systems Inc. (Nasdaq: BRCD) recently threw its weight behind open source SDN, introducing the Vyatta Controller based on OpenDaylight. (See Brocade Debuts OpenDaylight SDN Controller.)

In the commercial marketplace, VMWare and Cisco are the two giants competing for control. Cisco's SDN weapon is its Application Centric Infrastructure (ACI), while VMware's arms itself with its NSX software.

Cisco and VMware support the philosophy that intelligence should be in the software, but Cisco's proposition supports its own proprietary hardware that shares network management responsibilities with its controller. VMware runs as a layer atop other companies' networking hardware.

Other companies fighting for SDN market share have mostly developed products that are based on the OpenFlow protocol and its associated networking philosophy. OpenFlow is the vanguard of the pure SDN approach.

And it's not just the vendors that are developing SDN controllers: AT&T Inc. (NYSE: T) is developing a home-grown SDN controller. (See AT&T Working on Home-Grown SDN Controller for Later in 2014 .)


Want to know more about SDN? Visit Light Reading's SDN architectures content channel.


One of the major considerations for data center and network operators looking to deploy SDN controllers is whether they are truly interoperable and multivendor: One of the main promises of SDN is that it will free operators from vendor lock-in.

Multivendor support is a big deal, notes Roz Roseboro, senior analyst at Heavy Reading . "Operators don't want to be tied down. They don't want the choice of controllers to influence what switches they can use. They want to mix and match with whatever integration work is required," Roseboro says. Operators want to be able to work with the networking hardware they have, without ripping anything out.

Operators also need to consider whether to adopt a centralized or distributed approach, says Roseboro, who is preparing a report on SDN controllers. "There are some who believe there should be a master controller that watches over everything, and others who believe some of the intelligence should be on the hypervisor so it can make local decisions," she says.

So, here is our list of SDN controllers. If there are others out there, we can easily add them in as they emerge. Let us know about additions and updates using the comment board below.

Next Page: Commercial Controllers

— Mitch Wagner, Circle me on Google+ Follow me on TwitterVisit my LinkedIn profileFollow me on Facebook, West Coast Bureau Chief, Light Reading. Got a tip about SDN or NFV? Send it to [email protected]

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Dukie 1/28/2015 | 2:36:09 PM
Re: AT&T? Is Adara Networks a future Player in this arena?
Mitch Wagner 1/9/2015 | 5:18:58 PM
Re: Which part of the network Atlantis-dude: A big question, too broad to address here, but possibly worthy of a follow-up article. 
Atlantis-dude 1/5/2015 | 1:41:21 PM
Which part of the network i.e. edge/core/dc/wan  enterprise/SP are each of these targeted to?
mhhf1ve 12/19/2014 | 5:04:15 PM
Perhaps this guide needs a wiki? I think at the rate this space is moving.. a wiki will be needed to keep up with all the players and updates and changes.
jhichert 12/19/2014 | 10:28:14 AM
Please add Company: Ocedo

Controller: Ocedo Connect, a cloud-based console for managing distributed enterprise networks. Combined with Ocedo Gateways, Switches, and Access Points, Ocedo Connect enables IT providers to centralize and automate WAN deployment and management.

About: Founded in 2013 in Germany, Ocedo's mission is to help organizations to be more agile and to grow faster by automating their distributed enterprise networks.

Find out more:
Mitch Wagner 12/12/2014 | 5:14:41 PM
Re: More controllers Good tips all. We do plan to update this so keep those suggestions coming!
Y(J)S 12/12/2014 | 6:16:44 AM
More controllers Please add Ryu (which you actually mention earlier) and Openmul to the open source list. Other controllers (for more exotic languages) are Trema, NodeFlow and FLOWer. There are also a large number of experimental platforms from the academic community. BTW, ONOS is built over Floodlight.

In the commercial list  I didn't see the Tail-f (now Cisco) NCS.

Y(J)S

 
jmcolna 12/11/2014 | 2:53:21 PM
Active Broadband Networks’ SDN Controller Mitch,

You overlooked Active Broadband Networks' SDN controller, which was announced earlier this year. Below is description from the company's most recent product press release:

Active Broadband has developed the industry's first Software-Defined Broadband Network Gateway (SD-BNG), which consists of the APG/80 Active Programmable Gateway, a pure software switch for high-performance packet processing that is fully programmable via OpenFlow control, and the Active Resource Controller (ARC), an SDN controller optimized for broadband service orchestration and delivery with real-time, dynamic QoE management. Controlling the APG/80 with OpenFlow, the ARC facilitates autonomous, simplified, traffic-driven service activation.  The ARC gains its intelligence by collecting, mediating and further processing real-time IP flow information provided by the APG/80 -- delivering usable, actionable QoE information to enable customers' service expectations to be met.   The ARC also automates the use of QoE information, dynamically modifying customers' services using OpenFlow control of the APG/80.  Based on Big Data technology, the ARC computes and displays experience metrics that provide both operators and their customers with visibility into service utilization and network conditions, as well as application usage.  The ARC's Big Data technology provides a platform for data scientists to either directly analyze broadband service information or to integrate broadband service information into a larger analysis platform. The ARC leverages technology developed for legacy OSS-based service management, and is a proven, robust platform that can be deployed as a virtual appliance or as software components on operator-managed physical or virtual platforms.
Mitch Wagner 12/10/2014 | 12:30:10 PM
Re: AT&T? Good question. Something to follow up on. 
R Clark 12/9/2014 | 9:37:02 PM
AT&T? Thanks for the handy guide.

Whatever happened to AT&T's SDN Controller? I wonder if they weren't actually referring to ONOS from ON.Lab. They said it would be out by year-end.
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