WAN accelerator appliances are used to optimize a Wide Area Network so that end users experience improved WAN performance. These appliances use various optimization techniques such as data deduplication, caching, and compression to speed the flow of information back and forth across the WAN. For example, commonly accessed data might be cached so that it is readily available whenever a user needs it. Since the data is cached locally, it doesn’t need to be retrieved, loaded, and transmitted across the WAN once again. This can save a significant amount of time when distances are great.