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Bringing the WAN up to cloud speed …

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Kathy Gibson at Gartner Symposium, Cape Town — Wide area networks (WANs) today are less than ideal. They were typically bolted together in a fragile mish-mash of technologies – but they are expected to cope with traffic that is doubling in volume every three years.
The type of traffic is also changing rapidly, and today’s WANs were generally not designed to cope with the new applications and media they are carrying now.
“On top of this, networking professionals are being asked to deal with the cloud now as well,” says Neil Rickard, networking analyst at Gartner.
He points out that a first challenge is the fact that there is no such thing as “the” cloud — there are many clouds, many providers and many applications that fit under the cloud umbrella.
Infrastructure as a services (IaaS), platform as a service (PaaS), software as a services (SaaS) — and many different types of SaaS — means it is impossible to design for one cloud.
Although bandwidth has improved , latency is still an issue — and is getting worse. Despite the fact that we now have almost unlimited bandwidth, poor performance is still an issue. And cloud-deployed applications compound performance challenges.
“So latency has become the big network problem,” Rickard says. “We can do things to improve this. But we can’t improve on the speed of light. We can always buy more bandwidth, but latency will never go away, no matter how much money I spend.
“I can reduce unnecessary latency but I can’t go beyond the speed of light floor.”
The main challenge the cloud presents to networking professionals is that they usually get told about it once it happens — without a chance to re-architect the network. This results in post-rollout trouble shooting rather than a planned process.
Networking professionals need to start off by thinking about the front end, connecting the user to the cloud. They need to enhance internet access, directly connect to critical cloud services, use WAN optimisation to boost performance, and ensure application visibility.
At the back-end, from the enterprise data centre to the cloud, we need to deploy high-capacity, low-latency networks. They should aim to provide bandwidth on demand through SDN for migration and peaks; and implement high-performance WAN optimisation.
The default connectivity for most cloud services is over the Internet, so improving Internet access is going to be important.
“But not all cloud applications are created equal,” Rickard points out. “Most organisations will look at the most critical applications, and those could be hard-wired to the enterprise data centre.”
The Internet access will still need to be beefed up for the other applications and cloud providers, but hard-wiring to the top three of four is feasible. It will improve resilience and security of those critical apps.
This can be done with direct cloud connectivity, either direct or via an exchange. It can also work well using distributed internet access with enhanced backbone.
The hot topic in the networking industry right now is software-defined WAN (SD-WAN), although there is still some confusion about what it is.
Rickard explains that SD-WAN is an edge device that can be used with various network architectures. It is essentially a lightweight replacement for a WAN router.
It should dynamically distributed traffic across multiple WAN connections, based on application policies. “It allows you to get away from box-by-box configuration, which is hard to manage dynamically. SD-WAN takes away some of the complexity constraints.
“It also lets you make central policy decisions about applications. So it’s a powerful tool for enabling us to guild hybrid WANs, reducing issues and freeing us from policy constraints.”
SD-WAN is at the peak of expectation, with about 6 000 enterprises already using it.
“If you are refreshing your WAN contract, you should look at SD-WAN as your solution for the future,” Rickard says.
The vendor landscape for SD-WAN is different from what network professionals are used to.
Gartner has identified about 40 SD-WAN vendors, competing with a handful of incumbents. While this list will inevitably get smaller, Rickard believes there is room for at least 20 of them in the market.
“We urge anyone looking for new products and services to cast your net wide, and look for the best possible RFP. It’s time to look beyond the traditional players.”
SD-WAN is now also available as a managed service, and this could help companies to insulate themselves from any risk associated with buying solutions from smaller players.
Rickard says there are a number of consumption models: they can do it yourself; buy it from network service providers, system integrators or managed service providers; or they can do employ a hybrid approach.
The network function virtualisation (NFV) trend aims to turn everything within the network into software. NFV platforms are now emerging where service providers offer an “app store” where functionality and services are available on demand, and can be deployed relatively easily.
“This turns the network into more of a cloud-like service,” Rickard explains. “This helps when smaller vendors are used, helping to derisk the SD-WAN deployment.”
These NFV services are expected to roll out widely over the next 12 months from a number of major network providers. SD-WAN is one of the services that enterprises will be able to run over NFV.