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Microsoft Outlines Software Defined Networking Benefits of Windows Server 2012

• By Kurt Mackie
• 08/23/2012

Microsoft announced on Wednesday that software defined networking (SDN) capabilities will be powered by the combination of Windows Server 2012 and System Center 2012 Service Pack 1 (SP1).

Those solutions haven't been released as products yet. A launch event for Windows Server 2012 is scheduled for September 4. Microsoft has said that SP1 of System Center 2012 will arrive in beta form in the second half of this year. Presently, System Center 2012 SP1 is at the community technology preview 2 stage. In any case, Microsoft is touting SDN capabilities that will be enabled by those combined products.

In a blog post, company officials argued that Microsoft's SDN capabilities will enable improved automation in multitenant networking environments. Moreover developers and Microsoft's partner community will be able to tap into those capabilities using open standards, according to the blog post, which was written by Sandeep Singhal, general manager in the Windows networking team, and Vijay Tewari, a group program manager in the System Center Virtual Machine Manager team.

What Is Software Defined Networking?
SDN promises to bring the benefits seen with server virtualization to the networking devices world. It's an architectural approach that creates manageability at the control layer of networking devices, avoiding proprietary approaches. That's one definition, derived from a white paper by the Open Networking Foundation. The Open Networking Foundation is a nonprofit consortium that promotes OpenFlow as the standard SDN protocol. Members of that consortium include Deutsche Telekom, Facebook, Google, Microsoft, Verizon and Yahoo.

Here's how the Open Networking Foundation defines SDN, according to an April 13, 2012 white paper:

"Software Defined Networking (SDN) is an emerging network architecture where network control is decoupled from forwarding and is directly programmable. This migration of control, formerly tightly bound in individual network devices, into accessible computing devices enables the underlying infrastructure to be abstracted for applications and network services, which can treat the network as a logical or virtual entity."

Microsoft offered its own SDN definition, citing the ability of its SDN solution to create virtual networks, control traffic flow and integrate policies across virtual and physical networks:

"In summary, SDN is about being able to configure end hosts and physical network elements, dynamically adjust policies for how traffic flows through the network, and create virtual network abstractions that support real-time VM instantiation and migration throughout the datacenter. This definition of SDN is, in fact, broader, than the definition currently used by many industry players who only focus on configuration of physical network elements. Our broader SDN definition includes programmability of end hosts, enabling end-to-end software control in the datacenter. Our definition also supports real-time changes in response to VM placement and migration. As we will see below, the integration of VM management and network control is important to facility automation and reliability in large-scale datacenters."

SDN is at the buzzword stage right now, but what's meant by the term seems to depend on the approach taken. Bob Laliberte, an analyst with the Enterprise Strategy Group, sees SDN falling into four basic approaches:

• "Centralized control with OpenFlow connection";
• "Centralized control with either a proprietary or other open (non OpenFlow) connection;
• "Centralized control with virtual switches; and
• "Distributed control plane software switch."

He emphasized that those technical details are still shifting, even as SDN grinds through a hype cycle.

"It is still early in the technology development cycle, and hype cycle, for that matter, so expect to hear more about each of these approaches, or even a combination of them as time progresses and each are given a trial by fire," Laliberte wrote in a blog post. "Enterprise organizations should take some comfort that many of the telcos and cloud service providers are on the bleeding edge of this technology and will help to sort out the viable technologies or better define which technology works best in which environment."

Microsoft's Software Defined Networking
Microsoft's SDN talk may have been prodded, in part, by recent moves by competing vendors. Last month, Oracle made headlines by announcing the purchase of Xsigo, a company making virtualized networking products. That announcement came shortly after VMware announced a $1.26 billion buy of Nicira, an SDN pioneer.

VMware's Nicira buy just represented "a late acknowledgement of the importance of SDN as a critical enabler for the cloud," according to a blog post by Jaron Burbidge, a business development manager at Microsoft New Zealand's Server and Cloud Platform business. Singhal and Tewari pointed to a Microsoft Research paper, "VL2: A Scalable and Flexible Data Center Network," as the basis for Microsoft's SDN approach, both in Windows Server and Windows Azure. They contended that it has influenced the rest of the industry on the subject of network virtualization, too.

"The Microsoft Research paper introduced the very idea of network virtualization, creating overlay networks in the data center on a per-tenant basis," explained Singhal, in response to an e-mailed question. "This work identified the need to enable multiple tenants to co-exist on a common physical network."

Microsoft uses the Internet Engineering Task Force's Generic Routing Encapsulation (GRE) Protocol, which is used to direct a tenant's workload. But its SDN approach also works with OpenFlow, which is used to program network switches, Singhal explained.

"GRE and OpenFlow can absolutely co-exist," Singhal stated by e-mail. "For example, NEC has developed an OpenFlow extension to the Hyper-V switch. We have demonstrated how Hyper-V Network Virtualization can direct where traffic needs to go, while NEC's OpenFlow controller directs how traffic should physically get to its destination. This, for example, allows you to have network virtualization co-exist with physical and virtual appliances in the network (e.g., by forcing traffic from a VM to be routed via an appliance on its way to the destination host)."

The blog post by Singhal and Tewari mostly focused on SDN capabilities enabled by Microsoft's Hyper-V 3.0 extensible virtual switch. The extensible capabilities of the switch provide greater network transparency that can be used by third-party companies for things like traffic monitoring, virtual machine security and the configuration of virtual appliances, among other uses. Microsoft's partners can tap those capabilities via plug-ins to the virtual switch.

According to Singhal and Tewari, companies that have integrated with the Hyper-V extensible switch include NEC (using an OpenFlow controller) and InMon (via a traffic monitoring extension). They also cited some companies making network appliances that will work with Hyper-V network virtualization, including IVO Networks and nAppliance. Microsoft's SDN technology is also undergoing some testing by hosting companies and enterprise customers, they explained.

When asked about the SDN automation benefits enabled by Windows Server 2012 and System Center 2012 Virtual Machine Manager, Singhal offered the following examples:

• "Through Hyper-V Network Virtualization, SCVMM automatically configures and deploys virtual networks across the data center;
• "SCVMM supports automatic configuration and management of load balancers; and
• "SCVMM automatically configures gateways, including cross-premise connectivity."

Singhal and Tewari contended that users will get the necessary tools, too.

"Most important, all of the tools you need to deploy Software Defined Networking are built right in to Windows Server 2012 and System Center 2012 SP1, Virtual Machine Manager," the blog stated. "You do not need to buy separate management tools or acquire separate product editions."