Hardware-Defined Networking: Bridging The Gap For Enterprise SDN

An enterprise data center has any number of servers that will remain attached to physical network ports because legacy applications are resistant to virtualization. In some cases, organizations are reluctant to replace hardware appliances such as firewalls or proxy servers with virtual equivalents. This means that a virtual network overlay must be able to connect to physical networks. Here is where hardware-defined networking helps, by connecting legacy enterprise systems to SDN infrastructure.

A new partnership between Midokura and Cumulus Networks advances the concept of hardware-defined networking by combining technologies like VXLAN Tunnel Endpoints (VTEPs), Open vSwitch Database (OVSDB), "network Linux," and white-box hardware to create low-cost networks that connect physical networks directly to overlay networks.

Midokura is one of the earliest companies to build a network controller (MidoNet) and use overlay networking for SDN. The company is growing from a strong base in Japan to the U.S. and Europe. Today, it's an active participant in the OpenDaylight and OpenStack communities, especially the "Group Policy" code that relates to developing northbound APIs for applications, along with Plexxi. By partnering with Cumulus Networks,Midokura will work to define deeper integration of its SDN controller with physical networking fabric, positioning itself for the enterprise market.

Hardware-Defined Networking

Hardware-defined networking uses a group of open standards to connect existing physical networks to the overlay network. Midokura is working with Cumulus Networks to define OVSDB data formats for the Cumulus Linux switch operating system that enables the orchestration of the hardware VTEP capabilities of the Broadcom Trident chipset. OVSDB is part of the OpenDaylight project that defines the southbound device configuration API between controller and devices and under heavy development with support from multiple vendors.

[For more details on VTEP and OVSDB, read "Inside VMware NSX" by Brent Salisbury.]

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VTEP is a general term to describe the process of encapsulation of network traffic in the switch silicon. The missing element is the configuration that determines the forwarding tables and connectivity, for example, in a network with dozens of VXLAN networks, which physical ports are part of which overlay network? Are the ports configured as routers or switches? The OVSDB protocol enables the Midokura controller to define the configuration of the switch and the ports to participate in the overlay networks. Note that other controller vendors are also working on the same ideas for hardware-defined networking.

Cisco ACI and VMware NSX Comparisons

Comparisons of Midokura's strategy with Cisco products are inevitable because of Cisco's market dominance. Last November, the launch of Cisco ACI was called hardware-defined networking because of its device-centric focus. Without a demonstration of the APIC controller or any other software, Cisco presented a few models of Nexus 9000 switches to an expectant audience. More recently, Cisco has been focusing on the software aspects and puffing up the future of ACI in distributed networks.

VMware with NSX is often seen to be providing public support to Cumulus and white-box networking more generally. It seems reasonable to expect that NSX will support OVSDB for VTEP integrationin the near future and offer hardware-defined networking too.

Physical Network Integration Is A Real Requirement

Cloud providers are early adopters of overlay networking and the current generation of SDN products target this market. But the real money is in the much larger and slower moving enterprise market. We will see more vendors target the key enterprise customer requirement for SDN to integrate with the existing physical networks.

Midokura is making a smart move to partner with Cumulus and get ahead of the competition. Customers looking for alternatives to VMware or Cisco could find this partnership very attractive. The primary attraction of white-box networking hardware is that it costs 30% less than the price of established vendors, which is a big motivation for companies to look seriously at this solution.

Meanwhile, Cumulus Networks continues to pile up the partnerships that are crucial to its long-term business model. The company is extending its high-profile hardware partnerships with Delland the Open Compute Project to SDN platforms through partnerships with Midokura and others.

I'll be talking more about data center network strategy, including hardware-defined networking in my session, "Building the Physical Network for the Software-Defined Data Center"at Interop March 31. Interop runs through April 4 in Las Vegas.