What are Application Turns ?
Application Turns describes the number of requests and corresponding responses sent by an application during the completion of a task. A single application request may result in multiple response packets, but still represents only one turn. The important thing to understand is that an application turn results in waiting the full roundtrip time between the client and server. On a LAN, this time is typically very small and has little impact on the application. On a WAN however, this roundtrip time can have a significant impact on the application. This is why many applications that work well on the LAN fail miserably on the WAN. The key to writing WAN friendly applications is to keep the number of application turns to a minimum. This can be accomplished by reducing the number of database calls or HTTP Gets in an application.
