Check sum

Question 1

Checksum

Answer 1

• Method of checking if data has been transmitted correctly
• Data is sent in blocks and an additional value is placed at the end of the block
• A value is calculated from the data and sent with the data
• Data is recalculated at the receivers end and compared with original checksum to identify error

Question 2

Echo Check

Answer 2

• When data is sent, this data is sent back again to the sender for confirmation.
• Sender compares the two sets to check if any errors occured
• not reliable