We are already seeing the benefits and capabilities of virtualization as described in various Techopedia articles. Now it seems we may need a new network architecture to take the place of the old-but-reliable Open Systems Interconnection (OSI) model. Technologies like software-defined networking (SDN) and network function virtualization (NFV) are paving the way for a whole new world of networking.


Hardware can be a problem. Charles Babbage knew that well in the early 1800s. The design of his Difference Engine – which was never completed – would require 25,000 handmade parts. Computer manufacturers of the 20th century developed of a whole host of physical devices that network designers struggled to integrate into manageable network infrastructures. Today experts are working to eliminate much of the hardware altogether. (For more on virtualization, see Virtual Networking: What's All the Hype?)

Two important technologies have arisen to make virtualization happen. Software-defined networking allows network administrators to use white box switches as elements of a networking ecosystem that reduces the infrastructure to a commodity. The centralized control offered by SDN through platforms like OpenFlow and OpenStack are major components in the drive toward cloud computing.

While the focus of SDN has been on the data center, network function virtualization is the brainchild of network service providers. At the 2012 “SDN and OpenFlow World Congress” in Darmstadt, Germany, a group of major telecommunications providers teamed up to present a white paper introducing NFV to the world. The result was the formation of the Industry Specification Group (ISG) for Network Functions Virtualization within the European Telecommunications Standards Institute (ETSI).

The white paper showed how NFV would be “highly complementary” to SDN, but not dependent on it. It spelled out that NFV would reduce CAPEX, OPEX, and space and power consumption. Use cases included replacing a whole host of physical network components with software equivalents. The list includes switches, routers, mobile network nodes, VPN gateways, AAA servers, load balancers, and security devices such as firewalls, virus scanners and intrusion detection systems.

A New Model

Implementing these new technologies requires a new architecture, and a new way of thinking. For years those of us who have worked to develop, implement, and maintain the internet – or our little part of it – have been used to referring to the OSI model as our framework of understanding. Since its inception, many other protocol stacks have come alongside it to explain particular technologies in great detail. Now that we are faced with a virtualized network, perhaps we need a new network model. (For hazards to watch out for, check out 5 Things That Can Bog Down Virtual Infrastructure.)

Light Reading's Stephen Saunders has provided something for us to work with in a graphic on the website's “About Us” page. He calls it “A Network Model for the 21st Century” and lists the layers:

  • L4: Telco Cloud
  • L3: Open Source Network Software (free, virtualized)
  • L2: Net of Nets
  • L1: White Box, commoditized network and server hardware

In their white paper “Software-Defined Networking: The New Norm for Networks,” the Open Networking Foundation called for a new network architecture to deal with the challenges of burgeoning networks. The Software-Defined Network architecture has three layers:

  • Application layer
  • Control Layer
  • Infrastructure Layer

The Current State of Play

There is plenty of buzz about SDN and NFV these days, and lots of activity. ETSI's David Boswarthick stated in a video that there has been a “rapid increase in participation” in the NFV ISG. Steve Saunders of Light Reading seems excited about NFV. In his 4/19/2016 article “NFV: Coming, Ready or Not!” and the accompanying guide, Saunders quotes Caroline Chappell of Heavy Reading: “2016 is the year all operators will start doing something about NFV.” He says that 700 companies claim to sell more than 1,000 NFV products and services.

The potential benefits of “abstracting the network” through virtualization have been made clear. As with any new technologies, it may take a few years before everything shakes out, standards are adopted, and the full advantages of implementing the changes are realized. But the warning in Light Reading's NFV guide is clear: “Service providers that want to survive into the third decade of the 21st century need to start deploying NFV now.”


However the new environment is viewed, it is clear that the dependence on proprietary systems is becoming a thing of the past. As “hardware” vendors virtualize their network appliances and attach themselves to the new open ecosystem, and software creators develop APIs to connect as well, network service providers will be looking for new ways to implement and manage within the new framework. David Kirkpatrick, the CEO of Techonomy Media wrote, “Regardless of industry, your company is now a software company, and pretending that it's not spells serious peril.” That couldn't be more true for information technology providers today.