WAN optimization, or acceleration as it is sometimes called, is a hot and growing area in networking. Though vendor implementations vary, the general concept is the same. The technology is designed to enhance application performance and improve the user experience without having to increase bandwidth or reduce latency.

But the introduction of these new devices brings with it a dilemma: which group in your organization is on the hook for ownership, configuration and management?

The appliances use a mix of techniques that goes beyond simple caching to manipulating application traffic flow. Appliances by vendors such as Riverbed, Expand and Blue Coat provide solutions that are technically slick yet, if you consider the recurring cost for circuit upgrades, relatively inexpensive. So far, the results seem positive.

But in many organizations there is an administrative division between the network group and the systems group. The division somewhat follows the 7-layer Open Systems Interconnection (OSI) model. Network engineers spend most of their time working on circuits, switches and routers in OSI layers 1 to 3, venturing into layer 4 for access lists or quality of service configurations. You tend to find your IT staff further up the stack busy working on PCs, servers and applications.

Click to see: 7-layer Open Systems Interconnection

Sure, network engineers tend to know something about operating systems and upper layer protocols. And IT engineers usually know some networking. But the level of knowledge one has of the other is usually limited to just what is needed to complete work in their main functional area. Even though you’ll find exceptions, staff expertise tends to be one way or the other.

WAN Optimization appliances tend to configure like a router or switch. They generally contain a Command Line Interface (CLI) and Graphical User Interface (GUI) for configuration and management. In some implementations you must make network configuration changes on routers or switches to redirect traffic to the appliances. Routing protocols, load balancing and asymmetric traffic flows all must be considered during the design.

On the other hand, the appliances also behave like an application proxy. They contain application-layer intelligence and are aware of many upper-layer protocols. They insert themselves in the application flow and manipulate traffic in ways routers do not. The appliances alter TCP window sizes, cache data for future retrieval and only forward data blocks that have changed rather than entire files. They usually have hard drives. To implement the appliances properly, you must understand your applications’ behavior and configure the devices accordingly. The vendors do a good job of making it as simple as possible, but it is not exactly plug-and-play.