c3270 opens a telnet connection to an IBM mainframe host in an Xterm window or Virtual Console. It can also connect to an IBM AS/400 as a 5250 terminal using the AS/400's 3270 emulation. . c3270 is similar to tn3270(1), and x3270(1) except that it is curses-based, not X-based. . c3270 implements RFCs 2355 (TN3270E), 1576 (TN3270), and 1646 (LU name selection), and supports IND$FILE file transfer.