Apr 11 2011 10:56AM GMT

What is WAN optimization, anyway?

Tessa Parmenter Profile: Tessa Parmenter

Is WAN optimization a blur?

I’m surprised to find that there is still confusion as to what WAN optimization is these days. After all, one of the Gartner Magic Quadrant 2010 takeaways was that the WAN optimization controller market had matured and become a necessity for most enterprises. Instead of enterprises considering WAN optimization after users complain about slow response times overseas, businesses are adding WAN optimization to the beginning stages of network design. But what is it exactly that multi-site companies are needing and planning to use?

The definition of WAN optimization on WhatIs.com highlights that people use “WAN acceleration” and “WAN optimization” interchangeably — reasonable enough. While Dictionary.com doesn’t consider “acceleration” and “optimization” synonyms, its computer definition of optimize means “to write or rewrite (the instructions in a program) so as to maximize efficiency and speed in retrieval, storage, or execution.” “Accelerate” just focuses on the speed part of the optimization definition, making “WAN optimization” probably the most accurate term.

Still, different analysts and especially vendors will call various WAN bandwidth optimization tools different things.

“A number of players will say QoS is WAN optimization,” Dragon Slayer Consulting president Marc Staimer said to me in a recent conversation. His school of thought does not lump QoS, quality of service, into the sum of WAN optimization: “QoS or packet shaping is not really WAN optimization, but a lot of people call it that.”

He said what WAN optimization really does is this:

Reduce TCP latency.
Increase throughput.
Mitigate packet loss, which can result from high bit rates, jitter or congestion.

“In some cases … [WAN optimization is] done by caching data locally, [where data] just interchanges between the sites. In other cases, it’s done by terminating the protocol and running a proprietary protocol between the sites — a variety of different methodologies,” Staimer says.

These methodologies are so variant that some analysts insist certain “WAN optimization vendors” are not what they categorize themselves to be. In discussing the various WAN optimization techniques used by multiple WAN optimization vendors, I mentioned Blue Coat, to which Staimer replied, “They do things like Web caching and call it WAN optimization, and I kinda scratch my head and ask ‘Is that WAN optimization?'”

Analyst Jim Metzler includes Blue Coat in his snapshot comparison of WAN optimization vendors. And of course, Blue Coat Systems calls itself a WAN optimization vendor.

Will different techniques broaden the definition of WAN optimization? Maybe to some, but as WAN optimization technology evolves, perhaps the definition will follow suit.