Internet technological trends indicate that the link transmission speed has been significantly improved in the last decade, while the network nodes (routers and switches) have become the common bottleneck of Internet. Based on this insight, this paper applies the newly developed Visualized IP-based Network Simulator (VINS) to study TCP/IP networks formed on fast speed links. VINS design complies with the related RFCs and BSD operating system in three ways: IP networking; socket hosting and interfacing; service on the node. Two sample scenarios are presented regarding IP networking and TCP end-to-end congestion control for bulk data delivery such as video files, and handling packet overflow and delay on intermediate nodes.