WAN Optimization: Adding WOW to the WAN

You can’t be too rich, too thin or — in today’s environment — have too much bandwidth. How to achieve the first two goals is anybody’s guess, but fortunately the third is well within reach, thanks to WAN optimization technologies.

Traditionally used to speed communications among branch offices and headquarter locations, WAN optimization controllers (aka WAN optimizers) use data compression, information caching and other techniques to keep data volumes to a minimum and reduce latencies over wide-area communication links.

The result? Organizations can improve performance while delaying or even avoiding upgrades from traditional T1 or T3 WAN services to pricier optical networks.

In addition, the enterprise can consolidate resources in one central data center. The costs of managing data at remote locations can be reduced. And remote users will benefit from a more responsive network infrastructure, thereby increasing productivity.

Making the Most of Bandwidth

Workforces are becoming increasingly dispersed, with employees needing network access from a wide range of locations and devices. That’s why wide area networks need to be as fast, flexible and reliable as possible. But with more data traveling between more people every day, the volume is starting to take its toll.

Unable to keep up with the demand, WANs are experiencing high latency and sluggish performance. Applications and multimedia files slow to a crawl, and end users can get frustrated.

What’s more, data backups, which already impact bandwidth and performance, can take even longer across a sluggish WAN. And a slow system raises security concerns when remote employees save local copies of files rather than work on the network. This can compromise confidential data and weaken data monitoring processes.

To address these issues, many organizations purchase more bandwidth. However, that can chip away at budgets and may not even solve latency issues. A better solution: Optimize your existing WAN, which can bring immediate improvements to performance and utilization — without the need to increase bandwidth.

Controllers Do More

Makers of WAN optimization controllers (WOC) have pushed these devices from their branch-office origins into new areas, says Paula Musich, senior analyst for enterprise networking and security at the technology advisory firm Current Analysis. “There have been a couple of new wrinkles in the WAN optimization market as vendors anticipate increased demand from new types of traffic traversing networks,” she says.

These new types of applications fall into four main categories:

• Desktop virtualization: Centralizing enterprise data and applications within data centers provides a number of management and security advantages. But WAN-connected end users often need the acceleration of optimization solutions to stay productive and avoid the frustration of slow screen refreshes.
• Cloud computing: Maintaining productivity also becomes a challenge as enterprises move essential IT resources to private and public clouds. “Some people may think that when you go to the cloud, everything is all rosy,” says Henry Tam, product marketing manager at WAN-optimization solutions vendor F5 Networks. “However, many organizations are going to see the same performance issues as with a branch office.”
• Mobile computing: As smartphones and tablet PCs become commonplace in enterprises, WAN optimization technologies will be necessary to help remote staff work as efficiently as those in the main office.
• Widespread video applications: By freeing up bandwidth to eliminate transmission latency, WAN optimization solutions keep live and recorded videos running smoothly for internal and external audiences, notes Steve Schick, senior director of corporate communications for Blue Coat Systems.

As WAN optimization uses expand, traditional applications will also remain important. For example, data center consolidation goes a long way toward boosting the utilization rates and efficiency of technology resources.

Keep in mind, this works only if competition for bandwidth and latencies, resulting from long-distance communications, don’t impair branch offices after local capacity moves to a main data center. Similarly, by eliminating redundant information before it flows to backup systems, WAN optimization helps organizations replicate data within allotted backup windows without ongoing investments in added WAN bandwidth.

Multiple Options

WAN optimization solutions come in a variety of form factors. The traditional form factor is an appliance, a box with integrated hardware and software that network administrators plug into WAN connections in data centers and branch offices.

The venerable hardware appliance remains the workhorse choice thanks to ease of installation and the ability to handle environments with the highest performance demands. The performance advantages of these appliances also make them a top choice if data encryption is common and processing power is needed to compute encryption keys.

More recently, manufacturers have begun marketing virtual optimization solutions, software-only optimizers that reside on data center or branch-office servers and tap into unused processing power. This option saves money by letting IT shops take advantage of existing server investments rather than buying new hardware.

Flexibility is another advantage: Network administrators can install and manage branch-office optimization solutions from headquarters. Here they can quickly perform upgrades or replacements.

A choice for organizations with field staff and remote workers is a virtual solution designed for mobile computers. These small-footprint optimizers share the resources of a notebook to compress data, cache files and overcome the effects of performance-draining protocols.

Product makers and analysts also point out that virtual optimization solutions are a good fit for cloud computing. Public-cloud customers typically don’t have the option of installing an appliance within their service provider’s infrastructure, but they can readily add a virtual WAN optimizer to a shared server and fully optimize network traffic to and from the cloud.

Because virtual optimization solutions don’t run on dedicated hardware, performance may be slightly less than with a high-end appliance. Although the differences are real, the gap — typically 2 or 3 percent degradation — will be insignificant to many users.

Finally, a fourth form factor is now gaining traction in branch offices. It’s an appliance that comes with enough processing power to also run a variety of local resources. These can include printer servers, Microsoft Active Directory servers, web filters and security applications.

Core Components

The magic of WAN optimization results from a combination of technologies that can minimize the volume of traffic moving across networks and manage data flows as efficiently as possible. An integral part of the mix is the ability to apply data compression algorithms to reduce the volume of data that must pass over long-distance links. This keeps WANs from growing strained as demand increases, plus it speeds transmission times.

Data caching, typically at both the central data center and at branch offices, further enhances performance. The first time a user sends a large file from the main office, the WAN-optimization solution stores a local, branch-office copy on a hard drive within the appliance or on a network-connected storage resource.

Then, any time anyone at a branch office requests the information, they receive the local copy instead of initiating a transmission over the WAN. The local and headquarters optimization solutions can communicate with each other to determine if the file has been revised, and if so, send only the updates across the wire.

“With WAN optimization, organizations can eliminate 60 to 95 percent of the traffic across any one link,” says Miles Kelly, senior director of product marketing for WAN optimization vendor Riverbed Technology.

Organizations can use these tools as well to mitigate performance slowdowns caused by Transmission Control Protocol (TCP), Common Internet File System (CIFS), Server Message Block (SMB), Messaging Application Program Interface (MAPI) and other so-called “chatty” network transport standards.

“Chatty is defined by the number of round trips that take place between an end user making a request and the server that’s providing a file,” Kelly explains. “When you send a Microsoft SharePoint file from a server in New York to a server in San Francisco, for example, there are hundreds, if not thousands, of round trips that take place before that file is ever served.” Optimization solutions take charge by handling many of the necessary acknowledgement messages that typically flow over the WAN.

As more audio and video data traverses networks, organizations have to do more than just keep network pipes clear. This time-sensitive information needs special treatment.

Built-in, quality of service capabilities in optimization solutions do this a couple of ways. First, they limit available bandwidth to data packets that won’t be bothered by slight transmission delays. Second, they identify traffic that will receive top priority if bandwidth is in short supply.

Finally, optimization solutions can also act as an early-warning system for network administrators by constantly monitoring messages flowing among headquarters, branch offices and remote users. When transmissions begin to slow to unacceptable levels in a network segment, the optimization technology sounds an alarm before gridlock occurs. Some solutions even provide reports to help network administrators identify ongoing trouble spots.