An example of theis would be it is the protocol used to upload a new file to a cable modem.

TFTP is an extremely simple protocol to transfer files. It is implemented on the internet UDP layer (User Datagram Protocol) and lacks most of the features of FTP (see File Transfer Protocol (FTP)). The only thing it can do is read/write a file from/to a server.

Note: It has no provisions for user authentication: thus it is an unsecure protocol.

Any transfer begins with a request to read or write a file. If the server grants the request, the connection is opened and the file is sent in blocks of 512 bytes (fixed length). Blocks of the file are numbered consecutively, starting at

1. Each data packet must be acknowledged by an acknowledgment packet before the next one can be sent. Termination of the transfer is assumed on a data packet of less than 512 bytes.

Almost all errors will cause termination of the connection (lack of reliability). If a packet gets lost in the network, a timeout will occur, after which a retransmission of the last packet (data or acknowledgment) will take place.