Network the 'Next Big Thing' For Virtualization?

For the third installment of our examination of the current state of the virtualization market, after licensing and VMware competition, we take a closer look at the new virtualization paradigm in town: software-defined networking, also known as network virtualization. Names aside, it’s a technology that promises to be the next big thing for IT organizations, networking vendors and virtualization vendors alike.

In reality, the hype behind software-defined networking (SDN) started roughly a year ago with the creation of the Open Network Foundation (ONF), founded by Deutsche Telekom, Facebook, Google, Microsoft, Verizon, and Yahoo as a non-profit organization. The goal was to rethink networking, and quickly bring to market standards and solutions.

ONF is promoting the OpenFlow communications protocol as the heart of a SDN. OpenFlow was released as an industry standard at Interop Las Vegas 2011, and has since found its way into many vendors’ physical Ethernet routers and switches, virtual switches and access points. Development of the OpenFlow standard is now managed by the ONF.

What makes SDN Important?
In a software-defined network, switches and routers take some form of direction from a centralized software management element. In the context of OpenFlow, the control plane is abstracted from the data forwarding plane. A centralized controller, which maintains a real-time, holistic view of the network, defines network paths as "flows" and distributes this flow data to individual switches and routers. With these flows, the controller coordinates the forwarding of data across all network devices, enabling the automation and granularly managed dynamic provisioning necessary in virtualized environments and cloud networks.

SDN is certainly maturing, notes Eric Hanselman, research director for networks at The 451 Group. "People are actually starting to apply software-defined networking broadly, and OpenFlow [specifically], to solve some real-world problems," he says. "There are real applications where SDN provides some specific benefit.”

The Near Term
In a speech given at the October 2011 Open Networking Summit at Stanford University, Jonathan Heiliger, who helped found ONF and recently resigned as Facebook's VP of technical operations, said that the migration toward software-defined networks will move faster than carriers' migration to IP in the late 1990s. He claims that vendors and network administrators are starting to embrace SDN, driven by the need for network operators to have more control over their infrastructures and be able to customize them more for their own needs.

Heilgler thinks that just as the telecommunications industry once moved to IP from specialized systems such as ATM (Asynchronous Transfer Mode), it will adopt SDN in place of unique network architectures for each vendor. Adopting a common standard for SDN will help vendors to compete, just as IP did, but it will also help carriers deploy new services and even allow their enterprise customers to implement services between their own sites over the carrier network, he said.

Because of those motivations, the migration to SDN will take less time than the gradual move to IP, which took several years, Heiliger said. But it won't begin for another 18 to 24 months, he added. The entire software stack for SDN needs to mature first, he said.Heiliger explained that with OpenFlow a programmable controller is in charge of determining routes and priorities throughout a network. The controller implements the network configuration and settings via flow tables that reside on the switches in the network. OpenFlow is the common protocol for communication between controllers and switches from various vendors.

However, Heiliger also pointed out that the proprietary firmware in networking gear today constrains network operators, forcing them to integrate each vendor's technology into the network. "If I want to have a network management system, I have to figure out how to program my network management system to access the Cisco box versus a Juniper box versus some other third-party box," he said.

Likewise, the firmware in networking gear today constrains network operators, forcing them to build "wrappers" in their management software for devices from different vendors, he said. For example, to make sure a packet traverses the network with a certain quality of service, administrators need to make sure that the variables on a wide variety of gear are set correctly. They should be able to have that packet sent in the desired way without regard for the underlying network, he said: "I don't want to have to worry about it--I want another intelligent piece of software to have to worry about it."

More SDN Choices on the Horizon
The ONF doesn’t have the only game in town. Other vendors and IT businesses are looking to work together to establish SDN products. VMware, one of the leaders in virtualization technologies, doesn’t want to miss out on the potentially huge market that SDN offers and has recently teamed up with Stanford and Berkeley to create an industry consortium around SDNs, called the Open Networking Research Center. That consortium includes CableLabs, Cisco, Ericsson, Google, Hewlett-Packard, Huawei, Intel, Juniper, NEC, NTT Docomo and Texas Instruments as its founding sponsors. This ensures that VMware will have the technical support, collaboration and vendor interactions to create alternatives to OpenFlow.

VMware’s movement into the SDN market clearly shows that the vendor is interested in developing the software, standards and relationships to create SDN products, which will transform into a virtualization-based ideology, perhaps with the moniker of Virtual Networking Platforms. Alternatives and competition will prove to be important in the SDN market, since it will fuel adoption and innovation, as well as create more choices for customers.

What VMware is to virtualization, Cisco Systems is to networking, and it has its own plans for network virtualization, including a "spin-in" called Insieme, an internal startup that would develop SDN technology. It has received $100 million in funding and could receive up to $750 million.

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