A is a software application or hardware appliance that listens for incoming file transfer requests using the Trivial File Transfer Protocol. Unlike a standard file server (like FTP or Windows File Sharing), a TFTP server does not require user logins or complex directory browsing. It has one job: send a file or receive a file as quickly and simply as possible.
If an ACK is lost, the sender retransmits the last data block after a timeout (default 5 seconds). TFTP Server