Which protocol does FTP utilize for reliable communication according to IETF?

FTP (File Transfer Protocol) relies on TCP (Transmission Control Protocol) for reliable communication according to the standards set by the Internet Engineering Task Force (IETF). TCP is a connection-oriented protocol that ensures data is transmitted reliably between a client and a server. It accomplishes this through error checking, acknowledgments, and retransmissions of lost packets, making sure that the data is delivered in the correct order without any information loss.

FTP operates over TCP for several reasons: the protocol requires a reliable stream of data for transferring files, and TCP also manages flow control, helping to prevent the sender from overwhelming the receiver with data. As a result, FTP uses TCP to maintain the integrity and reliability of file transfers, which is crucial for applications that require accurate and complete data transmissions.

The other options do not involve reliable communication in the same manner as TCP does. UDP, for instance, while faster, does not provide reliable delivery, making it unsuitable for file transfers where accuracy is essential. HTTP (Hypertext Transfer Protocol) is used primarily for transmitting hypertext over the web, and SFTP (SSH File Transfer Protocol) is an extension of the SSH protocol and operates over TCP as well, but it is not the direct protocol used by FTP itself. Thus,