Abstract-The main goal of this paper is the analysis of the interaction between TCP and the UMTS link-level layer (RLC) to determine an optimal configuration for the parameters of both protocols. For this purpose, a web browsing simulation framework has been considered. This framework includes a web client accessing to remote HTTP servers through the UTRAN and Internet. The impact of the RLC configuration parameters on the behaviour of the multiple TCP connections simulated under this framework is analysed, showing their effect on web traffic performance.