Thursday, 28 March 2024, 05:16 AM
Site:
Webmaster Technology InstituteCourse:
Webmaster Technology Institute (AWS)Glossary:
Global Technical GlossaryZ
Z-Modem
: Also known as: Zmodem Z-Modem is an
error-correction protocol used in the transfer of serial data files
between modems. Z-Modem is a faster successor to Y-Modem and has
better error checking capability. Modems using the Z-Modem protocol
send data in 512-byte blocks or packets, and the error detection
method is cyclic redundancy check (CRC). Like Y-Modem, Z-Modem has
the capability of handling batch transmission (sending a number of
files with one command) and variable block sizes of data. Z-Modem
is also similar to Y-Modem-G, because it sends data in a continuous
stream, and does not require a positive acknowledgement (ACK) for
successfully transferred blocks of data. However, if an error is
detected in a received block, a negative acknowledgement (NAK) is
returned to the sender and the block resent. Z-Modem differs from
the earlier protocols in that it is able to recover after a
"crash", i.e. when a transmission is cancelled or for some other
reason interrupted, the transmission may be restarted without
resending the previously transferred blocks of data |
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