Answer to Question #317925 in Computer Networks for Aman

Question

Explain various error detection method? (5 marks question)

Answer 1

Error Detection Methods

• Single Parity Check – this is a technique in which an extra bit is added to the data to ensure the number of 1s either even or odd depending on which parity is in place. As a result, the receiver counts the number of 1s in a frame and if the outcome is even the frame is termed as uncorrupted hence approved.
• Checksum – this detection method applies a procedure that involves dividing the data into fixed sized segments. Subsequently, the segments are added by the sender using 1s complement arithmetic to obtain the sum. This then complements the sum which is used to obtain the checksum and sends it together with the data frames. The incoming segments are added by the receiver and then complements it. If the resulting outcome is zero, the received frames are accepted else they are rejected.
• Cyclic Redundancy Check (CRC) – this involves a predetermined divisor dividing data bits in a binary way. In this method, the incoming data unit is divided by the receiver in which the data unit is considered to be correct and accepted if there is no remainder. Otherwise, the data unit is assumed to be corrupted hence rejected.