The search for the software defined network

The average current-day Information Technology graduate, if placed in a time machine back to the 1970s, would find computer programming foreign and frightening.

Back then programming environments required explicit definitions, with language orientated towards what the machine required. Translation of human requirements to computer programming was, for the most part, the responsibility of the programmer.

Over the decades, abstraction of programming has led to languages that are progressively more human friendly. In modern programming languages, you type your instructions in a relatively intuitive syntax, then the programming environment maps those instructions to machine-level concepts.

No need to worry about memory address allocation, just worry about what Bob from accounting wants in his functional spec. Abstraction – the burden of translating human requirements to machine instructions has been transferred from programmer to computer.

One of the most telling demonstrations of this abstraction in the enterprise is the virtual server. Server hardware, and the associated overhead, has been hidden (virtualised, behind a software control layer named hypervisor) to provide ease of deployment, scalability, maintenance and efficiency for enterprises.

Of course, abstraction comes at a cost. Infrastructure needs to mature and become powerful enough to support the software control layer. (This is why Java could not run on 1970s microcomputers and had to wait until the power of 1990s workstations.)

“Networks haven’t changed for 30 years," says Greig Guy, country manager at Brocade. And with that warning, CIOs should now brace themselves for an onslaught of software-defined networking (SDN).

Abstraction of networks, or SDN, is the object of affection for the enterprise solutions industry in 2014.

Vendors say it’s about time that networks were abstracted. They plead, “Why is it that we now expect instant deployment of servers, but still put up with days of lead-time for networks to be configured and running?”

SDNs can range from a purely software model – hiding all the network ins-and-outs behind an all-encompassing hypervisor – all the way to mixed hardware-software architecture, which has software controlling certain proprietary hardware. And there are all the variants in between, like modular solutions that deploy components only as needed.

SDN is the last big puzzle piece towards the solution of a completely virtualised data centre – an ambition closely connected to cloud computing.

The scramble

This month alone we saw the release of open source SDN software project OpenDaylight, while tech giants such as VMware, Brocade, Juniper, Cisco Systems and others are each promoting contrasting interpretations of SDN in a mad scramble for early market share.

“We’re the largest network vendor on the planet, as far as port count goes,” says VMware spokesperson Aaron Steppat.

It sounds provocative, but the entry of the virtualisation specialist into networking has indeed unsettled traditional players.

As one might expect from a virtualisation specialist, VMware’s offering is software defined in the truest sense of the phrase. NSX, the proprietary name for the technology, is a hypervisor sitting on top of the hardware network, completely removing its visibility to other layers.

VMware says NSX will handle all the hard labour in a matter of seconds in response to network configurations that took hours or even days on a physical network.

The hard sell is now on in earnest.

“When we talk to our 500,000 VMWare customers, 77 percent of them are planning to have network virtualisation in their near term future," said Martin Casado, chief networking architect at VMware.

VMware is promoting NSX as a completion of the virtual data centre. The ideal world the company espouses is the pooling of all physical resources into one large pool then allocating them on an infrastructure-as-a-service (IaaS) basis according to need. Ideal, mind you, only if its VMware’s management console controlling these resources.

“The virtual data centre can be aligned to a tier of service – bronze, silver, gold, or platinum," says Steppat. “It can be aligned to a business unit… or in fact it could be a development life cycle. We could have a virtual data centre for test, development, pilot, and production.”

VMWare says the benefit of this is that any newly deployed application can inherit pre-defined policies of a virtual data centre, rather than having to setup infrastructure from scratch.

In July 2012, VMWare purchased Nicira, a company that was a pioneer of software-defined networking. Nicira provided the networking API towards OpenStack, a cloud computing platform; directed development of Open vSwitch, a virtual switch; and OpenFlow, network virtualisation software. Casado was one of Nicira’s founders.

Cisco’s approach to SDN is less dramatic – and arguably sceptical.

“I’ve had a dozen CIOs saying to me that SDN is a solution waiting for a problem," argues Kevin Bloch, chief technology officer of Cisco Australia and New Zealand.

“What [customers] are worried about is how to virtualise a workload – not a network," said Bloch. “So we virtualise the network, big deal. What are you doing about the storage? What are you doing about the compute? That’s the issue.”

The name of Cisco’s software defined network product - Application Centric Infrastructure (ACI) - reflects the company’s position. ACI provides a way of pre-defining network configurations to allow fast setup upon application deployment.

As a traditional vendor of network infrastructure, one may not be surprised to find ACI requires software be complemented with specific hardware, namely the Cisco Nexus 9000 switches and application specific integrated circuit (ASIC) technology.

The promotional catch phrase for it is “software flexibility with the scalability of hardware performance."

Cisco is playing to its strength, just as VMWare is.

Somewhere in between are the challenger networking brands such as Brocade and Juniper.

Using open source software and modular components, Brocade is seeking to differentiate itself from other providers by promoting how its SDN products will not lock clients into a specific ecosystem.

“There are three pillars – OpenStack, OpenFlow, and Vyatta," said Phillip Coates, systems engineering manager with Brocade ANZ. “With this model we can target for different environments.”

Coates said OpenStack is an overseer for multiple layers – compute, networking, and storage; and OpenFlow is a software controller for network traffic. Vyatta is the brand name for Brocade’s series of virtual routers that can be installed on white boxes, a notable achievement in itself.

Additionally, Brocade’s VDX hardware switches can also utilise pre-defined configurations for virtual machines.

“When I create a virtual machine in VMware, it automatically populates that personality into the Ethernet fabric. So when the application or virtual machine enters the fabric, I now know what VLAN it should live on, what storage it needs to connect to," says Coates. “And when it moves around to another place on that fabric, the policies follow the virtual machine.”

Brocade’s pitch is to avoid pushing one specific SDN model, but rather uses different components that can be deployed according to the customer’s choice of architecture. As such, the company doesn’t have an all-encompassing brand name for its software-defined network solution.

Cisco’s long time network hardware rival Juniper Networks launched its SDN product Contrail in September. Like Brocade, it espouses OpenStack and CloudStack compatibility to emphasise customers will not be trapped in a particular ecosystem.

While the concept of SDN has splintered many of these traditional vendor partners, all of those mentioned above and a host of others contribute code to the open source SDN project OpenDaylight.

The first version, Hydrogen, was launched February 4 at the OpenDaylight Summit held at Santa Clara, California.

The high-level concept is that OpenDaylight creates an industry standard to which vendors should build their products to.

Hydrogen comes in three editions of differing functionality and complexity – base, virtualisation, and service provider. The base edition is encouraged as an ideal way of implementing a proof-of-concept SDN.

Early days

With major vendors fighting for their model of SDN, 2014 will be an exciting year for this new market.

This month’s release of the open source SDN framework is a landmark that will allow enterprises to evaluate the concept inexpensively and decide which products best set their roadmap.

But as with any new concept, the small sample of existing customers, especially in Australia, is noticeable. All the vendors had difficulty providing examples of local customers to spruik their SDN offerings - assumedly because few organisations have the scale to experiment just yet.

VMware cited eBay and Citi as major US customers who have implemented SDN, but testimony from an Australian customer couldn’t be obtained at time of writing.

“SDN is at that stage where server virtualisation was about 10 years ago,” concluded Scott Maddox, a technical specialist at the City of Sydney.

“It's new, the benefits might be there in a few years, but businesses have too much CapEx invested in traditional switching infrastructure. Once a few early adopters have it working for a few years I'm sure most Aussie businesses will follow. In five years most places will use SDN by default. ”

The perfect cloud is almost with us.