Cyclic redundancy check
CYCLIC REDUNDANCY CHECK (crc)A method of checking for errors in data transmission using a division process.The data is divided into predetermined lengths and divided by a fixed divisor.
The remainder of the calculation is attached and sent with the data.When the data is received, the remainder is recalculated. If the remainders do not match, an error in transmission has occurred. There are a number of different standards for CRC. A 32-bit CRC achieves a 99.99% detection of all possible errors. Form part of many protocols including Ethernet, ATM & SONET Calculations of CRC values is generally built into and performed by the hardware. CRC checks as data is accessed from the drive- including hard disks, CD/DVD drives and also tape drives. Stronger technique for detecting errors than checksums and are far superior to simple parity checks. Values are calculated & included within the header of message packet by sender. Calculated using division whilst checksums use addition. ADVANTAGES AND DISADVANTAGES OF Crc
|
|