There are three key issues that cause application performance degradations:
- The bandwidth issue: The performance of many applications is related to the available bandwidth.
- The TCP issue: Design limitations mean that TCP is not able to utilise all available network resources.
- The application protocol issue: Many applications are not designed for the WAN but rather the LAN; they use chatty protocols, meaning that the application protocol relies on too high a ratio of protocol exchanges when transferring data. As network delay increases, their performance degrades significantly.