A frame check sequence (FCS) refers to the extra checksum characters added to a frame in a communication protocol for error detection and correction. A checksum is a form of Redundancy check, a simple way to protect the integrity of data by detecting errors in data that are sent through space ( Telecommunications In Computer networking, a frame is a Data packet of fixed or variable length which has been encoded by a Data link layer communications protocol for digital In the field of Telecommunications, a communications protocol is the set of standard rules for data representation signaling authentication and error detection required to In Mathematics, Computer science, Telecommunication, and Information theory, error detection and correction has great practical importance in
The sending host computes a checksum on the entire frame and appends this as a trailer to the data. In Information technology, trailer refers to supplemental Data placed at the end of a block of data being stored or transmitted which may contain information The receiving host computes the checksum on the frame using the same algorithm, and compares it to the received FCS. This way it can detect whether any data was lost or altered in transit. It may then discard the data, and request retransmission of the faulty frame.
The FCS is often transmitted in such a way that the receiver can compute a running sum over the entire frame, including the trailing FCS, and expect to see a fixed result (such as zero) when it is correct. Such an FCS generally appears immediately before the frame-ending delimiter.
By far the most popular popular FCS algorithm is a cyclic redundancy check, used in the Ethernet, X.25, HDLC, Frame Relay, Point-to-Point Protocol (PPP) and other data link layer protocols. A cyclic redundancy check (CRC is a type of function that takes as input a data stream of any length and produces as output a value of a certain space commonly a 32-bit integer Ethernet is a family of frame -based Computer networking technologies for Local area networks (LANs X25 is an ITU-T standard Network layer protocol for packet switched Wide area network (WAN communication High-Level Data Link Control ( HDLC) is a bit-oriented Synchronous Data link layer protocol developed by the International Organization In the context of Computer networking, frame relay consists of an efficient Data transmission technique used to send digital information In networking, the Point-to-Point Protocol, or PPP, is a data link protocol commonly used to establish a direct connection between two nodes The Data Link Layer is Layer 2 of the seven-layer OSI model. It responds to service requests from the Network Layer and issues service requests to the In the field of Telecommunications, a communications protocol is the set of standard rules for data representation signaling authentication and error detection required to