The authors analyze the performance of an end-to-end window-based flow control subject to bandwidth management. In particular, they model a high-level data-link-control-type layer-two protocol, e.g. LAPD, based on positive acknowledgements for correctly received frames. They explicitly model the effect of frame losses on the performance, which takes on a greater significance when some type of bandwidth management is used by the network. When a frame is lost, there are two major recovery mechanisms: REJECT and time-out. Both of them are explicitly incorporated into the analysis. The main performance measure considered is the goodput, i.e. the throughput of frames excluding retransmissions, that the customer can achieve. When the network is at a given level of congestion, it is shown that a customer can choose an appropriate window size to optimize the goodput subject to bandwidth management.>