& cplSiteName &

OpenFlow: Actually on the Ascent

Dan Pitt
Dan Pitt

I've been hearing it and you probably have been too: people questioning the future of the OpenFlow protocol or even proclaiming (perhaps wishfully so) its demise.

I would like to provide evidence to the contrary. While some industry players continue to argue over alternatives to OpenFlow, a wide range of network operators -- including major service providers, Internet companies and enterprises -- currently benefit from the control and vendor independence this open protocol provides. I've thought for some time that the industry needs to shift its attention from the southbound side (of the control plane) to the northbound (application) side, where SDN touches real business value, and now it is.

OpenFlow is the standard southbound protocol designed for SDN and it's vendor neutral. Nothing else is. It's now appearing in chipsets, white-box switches and branded switches, in addition to the hypervisor switches where it's been pervasive. With forwarding and control separate, OpenFlow-based switches offer amazing price-performance, while separate control software allows operators to tailor the network's behavior to their business priorities. This, of course, is the goal of SDN.

I can talk all day long about vendors implementing OpenFlow, but hearing from organizations that are buying and using it more strongly counters the contention that it's going away. At the Open Networking Summit (ONS) in June, four of them -- Alibaba Group , Google (Nasdaq: GOOG), AT&T Inc. (NYSE: T) and the US National Security Agency (NSA) -- revealed their reliance on OpenFlow; further evidence appeared at the OpenDaylight Summit in July.

For the most part, the point was not, "Hey, we're using OpenFlow!" Rather, it was, "Look at this amazing network we're building with SDN, and oh, by the way, how we do it is with OpenFlow" (and other things too, of course).

Scale and the white box revolution
At Google and Alibaba, the sheer size of their networks poses significant scale, cost and availability challenges. As Google Fellow and Technical Lead for Networking Amin Vahdat has noted: "We couldn't buy the hardware we needed to build a network of the size and speed we needed to build. It just didn't exist."

Consequently, Google has been building its own distributed computing and networking infrastructures. Three years ago at ONS, Senior Vice President of Technical Infrastructure Urs Hölzle disclosed that Google had converted its worldwide data-center interconnection network to a pure OpenFlow network. What they were doing inside their data centers, however, remained an object of speculation.

Last month, Amin Vahdat disclosed what many of us suspected -- that Google is using OpenFlow within the data center, too. The company is now on its fifth generation of a homegrown data center network, known as Jupiter, which utilizes an SDN architecture and OpenFlow, along with a centralized software control stack. OpenFlow provides a convenient abstraction to express remote procedure calls for programming forwarding table entries in these switches, Amin says, and gives Google the flexibility to swap in a range of hardware.

AT&T's universal customer premises equipment (CPE), meanwhile, is based on an x86 server with a virtualization layer that includes Open vSwitch (OVS) and hosts a number of virtual network functions. The carrier uses OpenFlow to configure OVS to service chain the appropriate flows among functions. As they convert more and more hardware-based functions to virtualized network functions in software, service chaining will be pervasive. At the OpenDaylight Summit, VMware's Director of Switching Technology and Leading OVS Developer Justin Pettit said that OVS implements OpenFlow and always has. VMware continues to be a major contributor to the evolution of OpenFlow in ONF.

Alibaba, the Chinese e-commerce giant, operates on a scale few of us can imagine. Digital Marketing Ramblings reported in April that Alibaba had 350 million active users, and its business exceeds the combined total of all the big US e-commerce companies. As Alibaba's participation in ONF (including significant leadership roles) has ramped up, we’re starting to gain some insight into how they handle such volume.

At ONS, senior networking architect Kitty Pang took the big stage to discuss Alibaba's hybrid SDN cloud network, which is built on OpenFlow (and VxLAN). Kitty explains that OpenFlow is simple, agile, well supported by vendors and better than the alternatives, like BGP and I2RS. Its use has also led to rapid development time of less than six months.

It's all about control
OpenFlow is flow-based, allowing individual flows to be treated precisely and uniquely. Thus it has been particularly appealing to the National Security Agency (NSA). The agency is currently using OpenFlow-based SDN in several small-scale deployments in its data center and branch office networks and is planning several major deployments during the next 12 months, according to Bryan Larish, NSA technical director for enterprise connectivity and specialized IT services.

I have visited NSA's extremely knowledgeable staff, and Bryan participated in ONF's Appfest in May in San Jose, Calif. At ONS, Bryan made some pretty blunt statements expressly about OpenFlow, such as, "Centralized control via OpenFlow is key," and "We are all in on OpenFlow."

I asked him, "Why OpenFlow?" Bryan responded: "We want a centralized control plane; we want that control plane to have predictable, fine-grained control over device behavior (ie. control at the flow level); we want to do all of that in a multi-vendor way. OpenFlow is the only protocol I'm aware of that meets these requirements. My intent is to make the OpenFlow/SDN/centralized control model our default solution."

I've heard many well-known enterprises -- and some smaller ones too -- express the same satisfaction with OpenFlow.

The new norm
I’m frankly a little surprised that the debate about the southbound protocol has gone on so long. After all, OpenFlow represents a vendor-neutral standard that does just what SDN is supposed to do. The alternatives are either not standard, vendor-specific, designed for some other purpose and not an ideal fit to the requirements, or artifacts of hardware-defined networking that fail to yield the value of SDN.

Business transformation is the most important benefit of SDN, not OpenFlow. But OpenFlow is the key to what network operators are looking for: freedom to build best-of-breed networks that can be uniquely programmed to meet their specific needs. I know of major, even incumbent, vendors that incorporate OpenFlow in their products but advertise the business benefit of their solutions, not the technology under the covers.

I challenge the promoters of southbound alternatives to demonstrate a superior overall means of delivering SDN's benefits. Hearing from bellwether operators that OpenFlow is their choice should be impetus enough for the industry to focus on system performance, interoperability, operational ease, effective management and application and service integration, which have greater direct impact on the bottom and top lines of businesses. Bickering over alternatives on the southbound side only delays these positive impacts.

— Dan Pitt, Executive Director, Open Networking Foundation

(3)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View        ADD A COMMENT
User Rank: Light Beer
4/7/2017 | 11:07:26 AM
yaxua gank tem 20gg
Openflow đang ở rất gần nhưng nó vẫn chưa chính thức trở thành 1 chuẩn phổ biến, lí do của việc đó có lẽ là việc thay đổi từ cầu trúc hạ tầng mạng hiện tại sang kết cấu openflow ở thời điểm hiện tại là chưa thực sự có thể  vì nhiều lí do. Openflow còn một chặng đường dài phía trước ,một chặng đường với nhiều thử thách
Faisal Khan
Faisal Khan,
User Rank: Blogger
9/7/2015 | 6:50:52 AM
Open flow
Good article !

One of the reasons OF could not get momentum is because of those vendors that have a lot to lose. ...They would try to prove that the alternatives are better


User Rank: Light Sabre
8/31/2015 | 3:28:32 AM
Still far away
No need to doubt the benefits of OF, yet! there is still a *lot* missing in OF. And a long long way to general usefulness of OF. Unless ONF speeds up the process of introducing the missing features, it risks OF to become obsolete before it really takes off.

More Blogs from Column
The shift to cloud is turning unified communications into the next hot service for enterprises as the UCaaS market continues to expand.
Pay-TV providers should focus on four key areas to bring employees and customers along for the ride.
The shift to cloud computing is changing the way business is done. Now, the CFOs and their finance teams are seeing a benefit in cloud as well.
As enterprises spread applications across multiple clouds, they need ways to maintain visibility and control, Ixia's Jeff Harris argues.
Going deep on how MIMO underpins the development of 5G.
Featured Video
From The Founder
Light Reading is spending much of this year digging into the details of how automation technology will impact the comms market, but let's take a moment to also look at how automation is set to overturn the current world order by the middle of the century.
Flash Poll
Upcoming Live Events
November 1, 2017, The Royal Garden Hotel
November 1, 2017, The Montcalm Marble Arch
November 2, 2017, 8 Northumberland Avenue, London, UK
November 2, 2017, 8 Northumberland Avenue – London
November 10, 2017, The Westin Times Square, New York, NY
November 16, 2017, ExCel Centre, London
November 30, 2017, The Westin Times Square
May 14-17, 2018, Austin Convention Center
All Upcoming Live Events
With the mobile ecosystem becoming increasingly vulnerable to security threats, AdaptiveMobile has laid out some of the key considerations for the wireless community.
Hot Topics
Muni Policies Stymie Edge Computing
Carol Wilson, Editor-at-large, 10/17/2017
Pai's FCC Raises Alarms at Competitive Carriers
Carol Wilson, Editor-at-large, 10/16/2017
Is US Lurching Back to Monopoly Status?
Carol Wilson, Editor-at-large, 10/16/2017
'Brutal' Automation & the Looming Workforce Cull
Iain Morris, News Editor, 10/18/2017
Worried About Bandwidth for 4K? Here Comes 8K!
Aditya Kishore, Practice Leader, Video Transformation, Telco Transformation, 10/17/2017
Animals with Phones
Selfie Game Strong Click Here
Latest Comment
Live Digital Audio

Understanding the full experience of women in technology requires starting at the collegiate level (or sooner) and studying the technologies women are involved with, company cultures they're part of and personal experiences of individuals.

During this WiC radio show, we will talk with Nicole Engelbert, the director of Research & Analysis for Ovum Technology and a 23-year telecom industry veteran, about her experiences and perspectives on women in tech. Engelbert covers infrastructure, applications and industries for Ovum, but she is also involved in the research firm's higher education team and has helped colleges and universities globally leverage technology as a strategy for improving recruitment, retention and graduation performance.

She will share her unique insight into the collegiate level, where women pursuing engineering and STEM-related degrees is dwindling. Engelbert will also reveal new, original Ovum research on the topics of artificial intelligence, the Internet of Things, security and augmented reality, as well as discuss what each of those technologies might mean for women in our field. As always, we'll also leave plenty of time to answer all your questions live on the air and chat board.

Like Us on Facebook
Twitter Feed
Partner Perspectives - content from our sponsors
The Mobile Broadband Road Ahead
By Kevin Taylor, for Huawei
All Partner Perspectives