4 ms·
FTP splitting the data and control ports was a smart implementation. It allowed for optimization of the ports (one focused on throughput) and meant that contro
by AdamN 3y ago
FTP splitting the data and control ports was a smart implementation. It allowed for optimization of the ports (one focused on throughput) and meant that control could still occur even while long responses were happening on the data port.
- sneak 3y agoThis could have been better accomplished by multiple connections to the same port.
- ajsnigrutin 3y agoA lot harder to implement QoS on that.
- sneak 3y agoQoS didn’t exist when FTP was invented. The protocol was designed badly.
- dark-star 3y agoit also allowed for FXP, which was a godsend in early pirating/warez days ;-) ...or so I've heard
- immibis 3y agoI haven't tested it, but I imagine it allows you to trick an FTP server into making an HTTP request (without TLS). It probably seemed like a good idea at the time, and there was no way to know the problems without trying it. It also allows you to send a command to cancel an ongoing transfer.
- ksherlock 3y agoWell... RFC 953 specifically mentions using PORT to send a file to a line printer so that seems intentional. [1] For streaming mode STORe/RETRieve the connection closes at the EOF so you could send the request but the response would be lost. [1] It is possible for the user to specify an alternate data port by use of the PORT command. The user may want a file dumped on a TAC line printer or retrieved from a third party host.