What's the difference between the telnetd and inetutils-telnetd packages in Ubuntu?

Question

1. Recently, a work came to me which needs to set telnet on linemode.so i install telnetd with apt install telnetd, which is controlled by inetd, and this operation will add new line telnet stream tcp nowait telnetd /usr/sbin/tcpd /usr/sbin/in.telnetd in /etc/inetd.conf
2. after install telnetd by this way, i tried many ways to enable linemode in telnet service yet all failed ,so i removed telnetd by apt remove telnetd
3. then i reinstall telnetd by apt install inetutils-telnetd, this operation also add new line in /etc/inetd.conf which is telnet stream tcp nowait telnetd /usr/sbin/tcpd /usr/sbin/telnetd.after doing this, i add a -l option in this line and restart telnetd. in this way, line mode is enabled and works well.
4. althrough work is finished, but still can't i figure out why these two ways are different. what's the difference between these packages telnetd and inetutils-telnetd

Answer 1

telnetd provides the netkit implementation of telnetd, whereas inetutils-telnetd provides the GNU Inetutils implementation. The latter supports the -l option to force line mode, whereas the former relies on negotiation with the client.

In most (if not all) cases, the Inetutils version of telnetd is more appropriate than the netkit version (within the limitations of the protocol).

See also What are the differences between iputils-ping and inetutils-ping?