QUIC is a multiplexed transport-layer protocol over UDP and comes with enforced encryption. It is expected to be a game-changer in improving web application performance. Together with the network layer and layers below, UDP, QUIC, and HTTP/3 form a new protocol stack for future network communication, whose current counterpart is TCP, TLS, and HTTP/2. In this study, to understand QUIC’s performance over high-speed networks and its potential to replace the TCP stack, we carry out a series of experiments to compare the UDP+QUIC+HTTP/3 (QUIC) stack and the TCP+TLS+HTTP/2 (HTTP/2) stack. Preliminary measurements on file download reveal that QUIC suffers from a data rate reduction compared to HTTP/2 across different hosts.