May 26 2011

Why Districts are Seeing WOCs in a New Light

WAN optimization controllers are essential as school districts embrace virtualization, cloud computing and other transformational technology tools.

WAN optimization controllers are essential as school districts embrace virtualization, cloud computing and other transformational technology tools.

Now that doing more with less has evolved from a strategy to a way of life within many IT departments, few technologies are getting a bigger boost than wide area network optimization controllers, or WOCs.

WOCs, also known as WAN optimizers, can be implemented as appliances or software applications. Either way, they work toward one overarching goal: making WAN links faster and more reliable without forcing school districts to spend more on bandwidth.

These controllers work by blending enhanced transmission control, data compression and data caching techniques to manage traffic moving across WANs and keep the volume of information to a minimum.

Why are districts now seeing WOCs in a new light? They address some of the most significant transformations occurring within IT infrastructures today:

    • Data center consolidation: Centralizing IT infrastructures reduces management overhead and helps hardware run closer to its rated capacity. But this is practical only if users within a district's scattered school sites don't see slower performance when their servers are no longer running locally.

      That's a big “if” without WOCs. The farther away servers and data reside, the more pressure WANs must bear as everyone competes for limited bandwidth. Another challenge is latency, the performance delays that crop up when clients and servers communicate over long distances.

    • Cloud computing: Similar challenges arise when servers, databases and applications reside in a public cloud. If IT managers can't maximize network resources to maintain acceptable levels of performance, cloud computing can't achieve its ambitious potential.

    • Replication and disaster recovery: An explosion in data volumes makes it harder for districts to perform regular backups within allotted windows, which ultimately could mean incomplete or lost information. Even so, most network managers don't have unlimited budget resources to pay for more bandwidth. WOCs boost efficiency by identifying and eliminating redundant files that clog networks.

  • Video: As live, on-demand video becomes a go-to technology for professional development efforts and student learning activities, districts are looking to WOCs to keep network channels flowing freely.

    “Among the trends that are driving WAN optimization to the next level, by far the biggest is video,” says Mark Urban, senior director of product marketing for Blue Coat Systems. “And that has an impact on WAN costs and the performance of other applications.”

    WOCs help by reducing network traffic and opening more bandwidth for latency-sensitive video transmissions. Some appliances can broadcast video to school sites by hosting and sharing their processing power with media servers that feed video streams to classrooms and desktops.

All of these considerations encourage districts to think differently about how they use and implement WOCs. “IT managers are no longer seeing WAN optimization as something they bolt on,” says Andrew Harding, senior director of product marketing for Cisco Systems. “It's something they plan for in their network designs.”

Behind the Scenes

WOCs work by taking a multipronged approach to optimizing WAN traffic. The first step is to compress data to keep volumes as low as possible. This keeps pipes from becoming overloaded and reduces transmission times.

For added performance, WOCs also cache information by storing files in local repositories – either in WOC appliances themselves or in networked storage systems. For instance, the first time someone in the district office relays a large presentation to a school, the WOCs would save a local copy.

Subsequently, when a remote user requests the presentation, it's delivered from that location rather than by traversing the WAN. The two WOCs can even communicate with each other to see if the presentation has been updated, and, if it has, the district office will download only the changes to keep redundant data from straining the network.

WOCs can overcome the cacophony of the ubiquitous Transmission Control Protocol (TCP) and other “chatty” network transport standards that require clients and servers to send multiple instructions and acknowledgements to one another in the process of exchanging data packets.

WAN optimizers, or WOCs, can boost file transfer speeds by 90 times in some cases. For a 100-megabyte file, that's a drop from 120 minutes to 30 minutes.

SOURCE: Silver Peak

The time between when messages are sent and when they're received can unnecessarily delay WAN transmissions. WOCs step in and handle many of the acknowledgement messages that typically have to travel across the wire. They're also designed to overcome the fail-safe measures of TCP when the protocol mistakenly slows traffic as it senses network congestion.

Protocol optimization doesn't stop with TCP. Many WOCs can use local message caching and other performance-boosting techniques on other talkative protocols, such as Common Internet File System (CIFS), Server Message Block (SMB) and Messaging Application Program Interface (MAPI).

As audio and video data on networks continues to grow, districts have to do more than just keep network pipes clear: Time-sensitive information needs special treatment.

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

Finally, WOCs can act as an early-warning system for network administrators by constantly monitoring messages flowing among district offices, schools and remote users. When transmissions begin to slow to unacceptable levels in a WAN segment, WOCs sound an alarm before gridlock occurs. Similarly, some WOCs provide reports to help network admins identify chronically slow spots.

What to Look For

With WOCs playing such an important role in addressing emerging IT challenges today, districts need to choose the right optimization solution for their needs. WOC manufacturers advise administrators to focus on six considerations when evaluating solutions.

    • Know the infrastructure. Target initial WOC investments to meet the immediate performance pain felt by end users and network administrators. Likely areas are core business applications, such as e-mail.

    • Look for implementation ease. WOC appliances should install directly into the IT infrastructure with one end of the network wire coming into the appliance from the router and another wire going out to a switch. WOCs should also be able to automatically identify and connect with one another no matter where they reside on the WAN. The best solutions provide a central console so administrators can manage all devices from one location.

    • Check for certification. Pay particular attention to how the WOC works with existing storage systems and individual enterprise applications.

      “Many of our clients compile a white list of applications that have been certified by the software vendors to work well with the optimization controller,” says Eric Siegel, research director for networks and telecommunications at Gartner. “Over time, the clients go back to the applications that are not being optimized and put them through the lab. If they work, then those programs are added to the list.”

    • Consider scalability and disaster recovery needs. WOCs should scale as throughput demands grow and as a district adds additional users and school facilities. Large districts and those with cloud implementations also should look for clustering capabilities that would allow multiple WOCs to be combined within virtual groups for automatic failover if an individual controller fails. WOCs also should dynamically handle spikes in demand when thousands of users are simultaneously accessing cloud services.

    • Plan for the unexpected. WOCs are reliable but not infallible. To guard against the disruption of a WOC breakdown, choose appliances that maintain network communications even if the optimization capabilities fail.

  • Look to the future. WAN optimization solutions need to be cost-effective when they're first implemented, as well as over time. Evaluate vendors' portfolios for long-term management costs and the ability to meet future needs. Individual site optimization may be the most important requirement today, but will the same platform also rise to the challenges of cloud deployments in the future?