Tiny devices with limited memory (e.g., industrial controllers, medical instruments) often embed a TFTP client for firmware updates because the code is small and easy to implement.
RHEL/CentOS Anaconda installer and Ubuntu Debian-Installer retrieve kickstart/preseed files via TFTP during automated network installs. TFTP Server
The server cannot send block #2 until it receives ACK #1. On high-latency networks, this makes TFTP painfully slow. Modern "TFTP Server" implementations often support TFTP Options (RFC 2347) like blksize (larger than 512 bytes) and timeout to mitigate this. Tiny devices with limited memory (e