RFFTP vs TFTP: Key Differences Explained
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This article explores the distinctions between FTP (File Transfer Protocol) and TFTP (Trivial File Transfer Protocol), two application-layer protocols used for transferring files across IP networks. We’ll delve into their functionalities, commands, and the scenarios where each protocol shines.
What is FTP?
FTP, or File Transfer Protocol, is commonly used for sending and receiving files from a remote computer. Defined in RFC959, FTP establishes two connections between the client and server:
- Control Connection: This connection handles commands and responses, managing the overall file transfer process.
- Data Connection: This connection is dedicated to the actual transfer of file data.
FTP Authentication
FTP requires authentication via username and password. Once authenticated, you can transfer files in both binary and text formats. When a FTP client requests a connection, a TCP connection is established to the FTP server’s port 21. Post authentication, another TCP connection is established on port 20 for actual data transfer.
Popular FTP Commands
While GUI-based FTP applications like FTP Commander PRO and FileZilla abstract these commands, understanding them provides valuable insight into how FTP works.
| FTP Commands | Description |
|---|---|
ftp | Starts the FTP client program. You can type ftp alone, or followed by an IP address or domain name. |
user | Changes the user ID and password information for the current session. Prompts for username and password upon initial ftp command. |
help | Displays available FTP commands on the client. |
ls | Lists the contents of the current directory. |
ascii | Switches the FTP client to ASCII transfer mode (for text files) from the default binary mode. |
binary | Switches the FTP client to binary transfer mode (for non-text files) from the default ASCII mode. |
type | Displays the current file transfer mode (ASCII or Binary). |
status | Displays current configuration settings on the FTP client. |
get | Retrieves a single file from the FTP server to the FTP client. |
mget | Retrieves multiple files from the server. |
put | Transfers a file from the FTP client to the FTP server. |
mput | Transfers multiple files from the client to the server. |
open | Opens a new session with the server. |
close | Ends the current session with the FTP server. |
quit / bye | Closes the current session and terminates the FTP client. |
What is TFTP?
TFTP, or Trivial File Transfer Protocol, defined in RFC783, offers a simplified approach to file transfer. It is simpler than FTP. It provides file transfer capabilities but lacks user authentication and other advanced features found in FTP.
TFTP & UDP
A key difference: TFTP uses UDP (User Datagram Protocol), while FTP relies on TCP (Transmission Control Protocol).
Because UDP is unreliable, TFTP implements its own application-layer recovery mechanism. This involves a small header between the UDP header and the data, containing codes for read, write, and acknowledgement, along with a numbering scheme for 512-byte data blocks. These block numbers acknowledge receipt and facilitate re-sending data in case of checksum failures. TFTP sends one block and waits for acknowledgement before sending the next.
FTP vs. TFTP: A Side-by-Side Comparison
| Feature | FTP (File Transfer Protocol) | TFTP (Trivial File Transfer Protocol) |
|---|---|---|
| Port Numbers | 20 (data) and 21 (control) | 69 |
| Transport Layer Protocol | TCP | UDP |
| Control Commands | Robust | Simple |
| Connection Management | Separate TCP connections | Connectionless (UDP) |
| Memory and Programming Effort | More | Less |
| Specification | RFC959 | RFC783 |
| Authentication | Requires User Authentication | No User Authentication |
In summary, FTP provides robust and reliable file transfer with authentication and various features, while TFTP offers a lightweight and simple solution, sacrificing security and features for speed and ease of implementation.
