Error correction and file transfer protocols typically work by calculating a checksum or CRC for a block of data known as a packet, and transmitting the resulting number at the end of the packet.
Transmission Control Protocol | File Transfer Protocol | Session Initiation Protocol | User Datagram Protocol | BitTorrent (protocol) | Kyoto Protocol | Internet Protocol | Post Office Protocol | Program and System Information Protocol | Simple Network Management Protocol | Internet Message Access Protocol | Network File System (protocol) | Hypertext Transfer Protocol | Lightweight Directory Access Protocol | Secure Real-time Transport Protocol | Real-time Transport Protocol | Simple Mail Transfer Protocol | Montreal Protocol | Communications protocol | Wireless Application Protocol | SSH File Transfer Protocol | Remote Desktop Protocol | Point-to-Point Protocol | Internet protocol | Dynamic Host Configuration Protocol | tunneling protocol | Trivial File Transfer Protocol | Real Time Streaming Protocol | Proprietary protocol | Network Time Protocol |