A very common form of file transmission, which can be used across dialup and telnet connections. It can be used in batch modes (for multiple files), and...
A file-transfer protocol commissioned by Telnet and placed in the public domain. Like Ymodem, it was designed by Chuck Forsberg and developed as an extension to Xmodem to overcome the inherent latency when using Send/Ackbased protocols such as Xmodem and Ymodem. It is a streaming, sliding-windows protocol.
an asynchronous communications protocol providing rapid data transfer with the enhanced ability to detect errors and allowing the transmission of larger blocks of data.
A file transfer protocol which transmits data between modems in blocks of 512 bytes. It is fast because it does not wait for positive acknowledgement (ACK) after each block of data, but will resend a block if it receives a negative acknowledgement (NAK).If a file transfer is interrupted, Zmodem can resume the transfer later and send only the part of the file that was not yet sent, which can save a lot of time. Zmodem is an advancement over Xmodem and Ymodem.
This protocol has many error-correcting properties. It can detect if a bad block (of 1,024 bytes) has come through and ask to have it resent. If the transfer gets interrupted for any reason, it can resume from where it left off. It is slightly slower than Ymodem-G, but is much more reliable.
a communications software product. See xmodem.
A file transfer protocol. It's the fastest of XMODEM and YMODEM and thus the most popular
An enhancement of the Xmodem file-transfer protocol that handles larger data transfers with less error. Zmodem includes a feature called checkpoint restart, which resume transmission at the point of interruption, rather than at the beginning, if the communications link is broken during data transfer.
ZMODEM is a sophisticated file transfer protocol developed by Chuck Forsberg in 1986, in a project funded by Telenet in order to improve file transfers on their X.25 network. In addition to dramatically improved performance compared to older protocols, ZMODEM also offered restartable transfers, auto-start by the sender, an expanded 32-bit CRC, and control character quoting, allowing it to be used on networks that might "eat" control characters. ZMODEM became extremely popular on bulletin board systems (BBS) in the early 1990s, displacing earlier protocols such as XMODEM and YMODEM.
