TN5250 stands for Telnet 5250. TN5250 is a protocol that provides remote terminal
access to an IBM AS/400 and iSeries computers. The TN5250
protocol allows this communication via a TCP/IP network instead of an
The computer that acts as a terminal is called the TN5250
client and the computer that acts as the host is called the TN5250
server. The TN5250 client computer must run an TN5250 client application (like TN3270 Plus) and the telnet server must run a
telnet server application. The TN5250 client received data streams
from the host computer and displays them in a terminal emulation
Windows. The contents of terminal emulation window mimic the screen of
an IBM 5250 terminal.
The TN5250 protocol is based on the IBM 5250 terminal
device which was sold with the IBM System/34 computer systems. The 5250
terminal was a block-oriented terminal similar to the IBM 3270 terminal.