In part one of this series on prioritizing WAN application delivery, we explored why simple carrier WAN QoS settings won't ensure that critical business applications will always get the network priority they need. Here in part two, we discuss which technologies can help.
There are a broad range of technologies that enterprises can use to prioritize WAN application delivery. Symmetric technologies like WAN optimization and asymmetric technologies like application delivery controllers can both help. And if an enterprise is mixing broadband links into its WAN, other technologies like WAN virtualization and aggregation can help, too. Even Web acceleration technologies that were once used only by Web content providers can become a strategic technology for WAN application delivery in the enterprise.
WAN optimization is the first step for any effort to prioritize WAN application delivery beyond simple WAN QoS, said Jim Frey, research director with Enterprise Management Associates.
"Most WAN optimization solutions have always been sold based on reducing the need for signing up for bigger, fatter pipes -- as a way to reduce the costs of the WAN services themselves. That is a tactical business model. [WAN optimization] is increasingly looked at as a means of improving and protecting application performance."
Rather than deploying WAN optimization to conserve bandwidth or to accelerate tasks like data center replication, network architects are using the technology strategically to prioritize critical business applications across the WAN. Vendors have recognized this shift from bandwidth conservation to application prioritization, and they have adjusted their technology focus. Riverbed Technology, a longtime leader in the WAN optimization market, has started rebranding itself as an "IT performance" company.
Read Part One
Prioritizing WAN application delivery: Go beyond WAN QoS
"It's great to make things faster, but we also need to make sure things are reliable and predictable," said Sidney Rabsatt, group product manager at Riverbed. "We've made a lot of investment in our QoS technologies over time, and recently we've made a stronger push, making sure we are solving problems that customers care about these days: unified communications and collaboration, voice and video, virtual desktop infrastructure and software as a service."
For effective WAN application delivery, understand your apps
Prioritizing WAN application delivery requires a good understanding of the applications running over the WAN. Vendors are stepping up their application intelligence efforts to meet that need.
"Look beyond the basic network information," said Mark Urban, senior director of WAN optimization solutions at Blue Coat. "You have to develop a way to classify applications using a lot of different techniques. 'This is HTTP, but it's HTTP traffic that belongs to Oracle or SharePoint or Exchange or other types of applications.' You have to build classification signatures for these applications."
Asymmetric technologies like application delivery controllers (ADCs) are playing an increasingly important role in application prioritization as well, Frey said. Although an ADC's core function is load balancing, this technology has a deep visibility into applications passing in and out of a data center. Also, they are asymmetric, unlike most WAN optimization technologies, which require devices on either end of a WAN link.
"Application delivery controllers are not usually brought in to deal with WAN issues, although they can help," he said. "They can do some of the same sorts of things [that WAN optimization can do], in terms of compression and caching to speed responsiveness. ADCs can be deployed in cloud settings more easily than WAN optimization."
Frey said the ADC's growing role in the WAN is reflected by who is buying it today. Traditionally, the application team has purchased them. However, recent EMA research found that the networking team is buying and deploying most ADCs.
Prioritizing WAN application delivery on broadband links
Many enterprises are adding commodity broadband links to their WANs, due to budget limits or the unavailability of MPLS services in some regions. In these situations, network engineers have virtually no SLA or QoS options from the carrier side.
"Instead of going through whatever path you're going to get through on the general purpose Internet, you hop on their highly groomed and optimized network," he said. Traditionally, a company like Akamai helped accelerate content for Web content companies, but the growth of enterprise applications on the Internet has created a new demand for such technology. "Akamai draws half its revenues from enterprises," Frey said.
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Other vendors specialize in build QoS engines that aggregate and virtualize multiple links, both enterprise-class links like MPLS and commodity broadband.
Talari Networks, for instance, has a technology called Adaptive Private Networking (APN), which aggregates multiple links to achieve better reliability and resiliency with broadband and other commodity networks. However, it also analyzes the quality of those links to determine where to send each packet. Then it applies its QoS engine to prioritize which applications use the best links at any given time.
"Our ability to provide resiliency is based around our own protocol," said Steve Dillon, system engineer with Talari. "I can make a decision on a network path selection event in sub-250 milliseconds. That's an order of magnitudes faster than any routing protocol."
Mark Blomquist, chief technical architect for Atlanta-based NCDR LLC, a provider of nonclinical services to Kool Smiles, a national provider of dental care, deployed Talari's APN technology to address network quality issues he was suffering with some rural T1 lines in in his MPLS cloud. He pulled those troublesome T1s and replaced them with multiple broadband connections virtualized by Talari. Now the technology is an essential part of how he prioritizes applications on his applications, including his two most critical WAN applications: Voice over IP and a dental practice management application.
"[Talari APN] gives us a much finer control over QoS than we would get with standard carrier-class QoS,” Blomquist said. "Don’t get me wrong; carrier-class QoS is leaps and bounds over what you can get from VPN backhaul, but it's not robust enough where you can keep all your users happy. I have 3,500 people clamoring for good network quality and the QoS from the carrier is OK. But the APN technology we rolled out in a few locations is far superior. It reacts to network conditions better.
"[APN] will aggregate diverse carriers and feed it into this system, and it will make intelligent decisions about jitter, loss and latency, things that are going on in the network in real time. And it will route around that. So VoIP will always make it, because APN will duplicate my VoIP packets across both links if I want it to."
Let us know what you think about the story; email: Shamus McGillicuddy, News Director
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