Performance Enhancing Proxies Intended to Mitigate Link-Related Degradations

This document is a survey of Performance Enhancing Proxies (PEPs) often employed to improve degraded TCP performance caused by characteristics of specific link environments, for example, in satellite, wireless WAN, and wireless LAN environments. Different types of Performance Enhancing Proxies are described as well as the mechanisms used to improve performance. Emphasis is put on proxies operating with TCP. In addition, motivations for their development and use are described along with some of the consequences of using them, especially in the context of the Internet.