Daily Archives: May 11, 2012

What the Battle for “SDN” Reveals

As Mike Fratto notes in an excellent piece over at Network Computing, “software-defined networking” has become a semantical battleground, with the term getting pushed and pulled in various directions.

For good reason, Fratto was concerned that the proliferating definitions of software-defined networking (SDN) were in danger of shearing the term of all meaning. He compared what was happening to SDN to what happened previously to terms such as cloud computing, and he opined that once a term means anything, it means nothing.

Setting Record Straight

Not wanting to be passive observer to such linguistic nihilism, Fratto decided to set the record straight. He rightly observes that software-defined networking (SDN), as we understand it today, derives its provenance from the Open Networking Foundation (ONF). As such, the ONF’s definition of SDN should be the one that holds sway.

Citing an ONF white paper, “Software-Defined Networking:  The New Norm for Networks,” Fratto notes that, properly understood, SDN emphasizes three key features:

  • Separation of the control plane from the data plane
  • A centralized controller and view of the network
  • Programmability of the network by external applications

Why the Fuss?

I agree that the ONF’s definition is the one that should be authoritative and, well, definitive. What other vendors are doing in areas such as network virtualization and network programmability might be interesting — and perhaps even commendable and valuable to their customers — but unless what they are doing meets the ONF criteria, it should not qualify as SDN.  Furthermore, if what they’re doing doesn’t qualify as SDN, they should call it something else and explain its architectural principles and value clearly. An ambiguous, perhaps even disingenuous, linkage with SDN ought to be avoided.

What Fratto does not explore is why certain parties are attempting to muddy the SDN waters. In my experience, when vendors contest terminology, it suggests the linguistic real estate in question is uncommonly valuable, either strategically or monetarily. I posit that SDN is both.

Like “cloud” before it, everybody seemingly recognizes that SDN has struck a resounding chord. There’s hype attached to SDN, sure, but it also has genuine appeal and has generated considerable interest. As the composition of the ONF’s board of directors has suggested, and as the growing number of cloud service-provider deployments attest, SDN is not a passing fad. At least in the large cloud shops, it already has practical utility and business value.

The Value of Words

That value is likely to grow over time, and, while the enterprise will be a tough nut to crack for more than one reason, it’s certainly conceivable that the SDN eventually will find favor among at least certain enterprise demographics. The timeline for that outcome is not imminent, and, as I’ve written previously, Cisco isn’t about to “do a Nortel” and hold a going-out-of-business sale. Nonetheless, the auguries suggest that the ONF’s SDN will be with us for a long time and represents a significant business threat to networking’s status quo.

In this context, language really is power. If entrenched interests — such as the status quo of networking — don’t like an emerging trend, one way they can attempt to derail it is by co-opting it or subverting it. After all, it’s only an emerging trend, not yet entrenched, so therefore its terminology is nascent, too. If, as a major vendor with industry clout, you can change the meaning of the terminology, or make it so ambiguous that practically anything qualifies for inclusion, you can reassert control and dilute the threat.

In the past, this gambit — change the meaning, change the game — has accrued a decent track record. It works to impede change and to give entrenched interests more time to plot effective countermeasures.

Different This Time

What’s different this time — and Fratto’s piece provides corroborating evidence — is the existence of the ONF, a strong, customer-driven consortium that is (in its own words) “dedicated to the transformation of networking through the development and standardization of a unique architecture called Software-Defined Networking (SDN), which brings direct software programmability to networks worldwide. The mission of the Foundation is to commercialize and promote SDN and the underlying technologies as a disruptive approach to networking that will change how virtually every company with a network operates.”

If the ONF hadn’t existed, if it hadn’t already established an incontrovertible definition of SDN, the old “change the meaning, change the game” play might have worked.

But, as Fratto’s piece illustrates, it probably won’t work now.