TFTP General Operation, Connection Establishment, and Client/Server Communication
Since the T in TF TP stands for Trivial, and the protocol was specifically designed to be simple, you would think that describing how it works would, in fact, be simple, wouldn't you? And, actually, that's pretty much true. TFTP communication is client/server based, as discussed in the overview. The process of transferring a file consists of three main phases:
Initial Connection The TFTP client establishes the connection by sending an initial request to the server. The server responds back to the client, and the connection is effectively opened.
Data Transfer Once the connection is established, the client and server exchange TFTP messages. One device sends data, and ...