The Three Faces of SDN
The loosey-goosey school
The other school of SDN tries to marry the SDN vision with traditional networks. The goal is to make the network more flexible, agile, and programmable, while making it easier for carriers and enterprises to preserve their network investment (and for vendors to keep selling what they've always been selling). This vision also has the advantage of making SDN purists turn red with anger and heat up until steam comes out of their ears, which is fun to watch.
Because it's embarrassing for grown people to say "loosey-goosey," people use "overlay networking" to refer to loosey-goosey SDN, because the SDN network is an overlay on top of the traditional network. Overlay networking is becoming mainstream now. It's embraced by companies including Cisco Systems Inc. (Nasdaq: CSCO), VMware Inc. (NYSE: VMW), and startups like PlumGrid Inc. and Midokura . (See Cisco & VMware Are Apple & Google of SDN and Midokura Does Net Virtualization at Web Scale .)
In the long run, overlay networks are doomed, as are the proprietary switches underlying them. But the long run is a long way away. The data can't wait for the long run -- the data has to flow now.
Both schools of SDN require enormous business transformations for carriers. Carriers will need new skills. They'll need to reorganize their networking departments around managing software, rather than hardware. How long will that transition take? Ask me again in 20 years or so. The data center transition to open systems is still sending shockwaves that show no signs of ending soon.
But wait, there's more
I discussed the competing visions of SDN with IDC analyst Brad Casemore, and he pointed out a third faction struggling for the networking market: The hyperscale cloud providers. These include Google (Nasdaq: GOOG) and Amazon.com Inc. (Nasdaq: AMZN) and service providers including CenturyLink Inc. (NYSE: CTL) and Verizon Communications Inc. (NYSE: VZ). Enterprise cloud providers are looking to eliminate enterprise networks entirely and run everything in the cloud. They're likely to achieve success in SMBs at first. For example, Pertino offers cloud VPN services for SMBs.
This model is potentially apocalyptic. If this model succeeds, the enterprise switch-and-router market would dry up, as enterprises basically outsource their networks entirely to cloud providers. These cloud providers are today major customers of networking vendors, but they are also competitive threats. Cisco is trying to play multiple sides in this game -- a loosey-goosey networking vendor and also a cloud provider with its Intercloud strategy. (See Cisco's Cloud Bet: What's in It for SPs? and Can Cisco Help SPs Offer Cloud-based Apps?)
It's like The Game of Thrones. This TV show, and the books on which it's based, tell the stories of warring noble houses in a mythical kingdom. Each one of these houses wants to be the one to put a king on the throne, and they are all-consumed with fighting each other.
But what none of these houses realize -- at least not yet -- is that there's a vast zombie army, called the White Walkers, assembling in the arctic far north of the kingdom, and the White Walkers threaten to descend on the kingdom and sweep all the noble houses aside.
In this metaphor, the houses of Westeros are the traditional networking vendors, and the White Walkers are the cloud providers.
— Mitch Wagner, 
, West Coast Bureau Chief, Light Reading. Got a tip about SDN or NFV? Send it to [email protected]
Want to learn more about SDN and the transport network? Check out the agenda for Light Reading's Big Telecom Event (BTE), which will take place on June 17 and 18 at the Sheraton Chicago Hotel and Towers. The event combines the educational power of interactive conference sessions devised and hosted by Heavy Reading's experienced industry analysts with multi-vendor interoperability and proof-of-concept networking and application showcases. For more on the event, the topics, and the stellar service provider speaker lineup, see Telecommunication Luminaries to Discuss the Hottest Industry Trends at Light Reading's Big Telecom Event in June.
