The aim of this article is to compare, from an experimental point of view, the TCP performance achieved using the TCP Reno with SACK (Selective Acknowledgment) implementation, and that obtained using the Snoop TCP proxy-based approach over an IEEE 802.11b wireless LAN. This study has been carried out in the context of the WINE (Wireless Internet Networks) project corresponding to the 5th framework of the European IST programme, addressed to enhance the performance of the TCP-UDP/IP protocol stack over wireless infrastructures such as IEEE 802.11, Bluetooth and HIPERLAN/2. The objective of this project is to develop a PEP (Performance Enhancing Proxy), named the WAL (Wireless Adaptation Layer), targeted at Internet protocols when they operate over wireless shared access LANs. The Snoop agent has been implemented as a module belonging to this layer.