The difference between QUIC and TCP is the original sin of TCP (and its predecessor) - that of emulating an async serial port connection, with no visible messag

The difference between QUIC and TCP is the original sin of TCP (and its predecessor) - that of emulating an async serial port connection, with no visible messaging layer. It meant that you could use a physical teletypewriter to connect to services (simplified description - slap a modem on a serial port, dial into a TIP, write host address and port number, voila), but it also means that TCP has no idea of message boundaries, and while you can push some of that knowledge now the early software didn't. In comparison, QUIC and many other non-TCP protocols (SCTP, TP4) explicitly provide for messaging boundaries - your interface to the system isn't based on emulated serial ports but on messages that might at most get reassembled.