My buddy, Derek Thompson, just started at Fishnet Security. Besides peddling Bluecoat and SonicWall Managed Services, he is also selling WAN Optimization. While I have heard of this, I had no idea what it was or how it worked. So Derek invited me to sit down with Doug Kruger of Riverbed. Doug explained it simply enough.

One reason companies consider WAN optimization is if the company needs more bandwidth. It may not need more bandwidth, it may just need to better utilize the Internet Access it already has.

Multi-location companies sometimes have servers at each branch instead of consolidating the servers in one data center. This saves money on maintenance and storage, but in some cases may mean a bigger pipe to access the servers in real-time from the data center.

By consolidating servers into one location can save on manpower, maintenance, and data storage/back-up costs. This is also the sales trigger for Virtualization and Cloud Computing. Save on hardware, labor and storage.

TCP and latency are other reasons that companies buy bigger pipe, when perhaps they could just optimize the current WAN connections (or change to MPLS pipes instead of DIA or dedicated Internet access circuits at each location). TCP is not the most efficient protocol, but it works, just sometimes creating excess packet traffic across the WAN.  Latency for real-time applications is also a real problem across the Internet. Lastly, many applications, including Microsoft Office, create excess traffic on the WAN when any document is being opened. 

One of the ways that companies like Riverbed optimize the WAN is to eliminate duplicate data traffic. It's called De-Dupe and the effect is to eliminate up to 80% of traffic across the WAN. WANO technology usually will work on eliminating all the excess packet traffic on the WAN, which will usually result in a bandwidth savings. 

Riverbed tweeks TCP headers to modify the TCP window sizing issue. The tech here gets beyond me and my discussion, but by modifying the TCP packet headers much of the TCP "noise" on the WAN is cut down. By diminishing the excess packet traffic from apps and TCP, WAN optimization technology is able to save a lot of bandwidth. 

Riverbed also works on application latency in a similar vein, by the mitigation of excess packet traffic from apps like Microcosft Office. The technology guesses what the application will ask for and deliver it all at once instead of in 20 different packet streams. Many Fortune 5000 companies use WAN Optimization due mainly to cost cutting force on them by the economy. Data is business critical, so any way that you can save money on the WAN is a good thing.