Zusammenfassung der Ressource
1.1.3 Data Storage: Error checking
- Parity
check
- Parity checking is used to check
weather data has been changed or
corrupted following transmission from
one device to another
- A byte of data is allocated a parity bit o
Systems that use even parity have an
even number of 1-bits o Systems that use
odd parity have an even number of 1-bits
- Automatic Repeat Request (ARQ)
- ARQ used acknowledgment to indicate
data receiver correctly.
- It uses and acknowledgement (message
sent by the receiver indicating that data
has been received correctly)
- Checksum
- Data is sent in blocks and an additional
value sent at the end of the block
- An additional value called Checksum, is end at the end of the block of data.
- The checksum is based on the number of bytes in the block
- If the checksum at the receiver’s end doesn’t match
the checksum at the end of the data block, then an
error in transmission has occurred
- Echo check
- Data is returned to the sender