By Michael Morisy
Software defined networking (SDN) not only cuts networking costs but could also help cloud providers better set and manage stringent cloud SLAs (service-level agreements), which are particularly important as customers become more savvy and demanding about getting the most from their dollar.
The cloud SLA-compliance benefits could apply to everything from uptime guarantees and the speed of time-to-deployment to security provisioning and bandwidth utilization.
DreamHost, which is transitioning from being a shared hosting provider to a cloud service provider, is running a virtualized network powered by Nicira to improve cloud SLA compliance and overall service agility.
"When it comes to SLAs, it gives us more flexibility. Just like with virtual machines, you can shift the network around as a logical unit," said Jonathan LaCour, vice president of software development at DreamHost.
DreamHost can operate with a leaner staff by relying on application programming interfaces (APIs) and automation to do much of the heavy configuration lifting instead of manually setting up a series of switches and routers, he said.
In addition to the lowered staff costs, DreamHost can offer drastically reduced deployment times and the self-service people have come to expect from cloud services.
"I've had some really interesting conversations at developer conferences talking to customers," LaCour said. Those customers want better cloud SLA "notifications and monitoring and the ability to self-serve changes instead of having to go through the process of contacting us and waiting for a new box to be provisioned. They want to be able to, in an API-enabled way, spin up new instances and move workloads."
SDN-enabled clouds can offer just that in a more consistent and repeatable way than previously possible, since each change to the network no longer requires individual provisioning and configuration.
With software defined networking, Calligo can offer more than uptime
SDN-enabled clouds also help providers better fulfill commitments around support.
Calligo, a cloud provider located in the U.K. Channel Islands, is also transitioning toward more a virtualized network with Nicira, partially in response to increasingly sophisticated cloud-SLA demands from customers.
"Their focus is not just on uptime, but performance and support, because they see you as an extension of their IT department or even their whole IT department," said Julian Box, CEO of Calligo. "Not just uptime but actual service."
These stringent support demands have pushed Calligo to offer more on-demand provisioning of services.
"The cloud promotes this perception that you can just click and get this and that from providers instantly," Box said.
Having an environment where everything is virtualized -- from the servers to the switches -- helps Calligo meet those expectations, since every element can now be managed as its own independent and logical piece, regardless of the current physical makeup of the network.
Software defined networking offers more reliable and tunable cloud SLAs and cloud security
Network virtualization and software defined networking also helps begin to solve one of the most frequently cited problems with enterprise cloud deployments: security. Specifically,SDN allows better partitioning and separation of resources and privileges among customers at Open Systems Interconnection (OSI) Layers 2 and 3.
"We can give customers their own [virtual] network, and that gives them some protection on a Layer 2 level in the cloud," said LaCour. "One of the big concerns is intermingling in the cloud. When it comes to our cloud and what we enable with network virtualization, we can provide each customer and tenant with their own network isolated from other customers."
That, said LaCour, gives customers the freedom to tighten controls around network access to their piece of the cloud infrastructure in ways more reminiscent of traditional hosting -- down to even having virtual machines with private addresses not available through the public Internet -- while still gaining the scale benefits of the cloud.
Cloud architecture is a fundamentally different and more predictable paradigm than traditional Internet architecture, and it operates at a scale where those efficiencies and capabilities start to add up, said Tom Nolle, president of CIMI Corp.
Within a cloud, according to Nolle, SDN can be used to define almost every aspect of how traffic flows, allowing the most efficient routes to be set by policy rather than the somewhat unpredictable, best-effort routing mechanisms of traditional Internet Protocol (IP).
That predictability, in turn, offers a more finely tuned product that can be reliably and repeatedly sold.
"As far as service providers are concerned, with the whole SDN environment, if you're not doing it now, I would be amazed if anyone is not doing it in 18 months, because their competitors will have an advantage over them," Box said. "The flexibility that this offers service providers is huge."