You will need both the xinetd and telnetd packages. Just run the command:
sudo apt-get install xinetd telnetd

Next, edit/etc/inetd.confusing your favorite file editor with root permissions, adding this line:

telnet stream tcp nowait telnetd /usr/sbin/tcpd /usr/sbin/in.telnetd

Next, edit/etc/xinetd.conf, and make its content look like following: If the file doesn't exit, create the file and make sure that the file permissions are --rw-rw-r- using chmod u=rw,g=rw,o=r xinetd.conf

# Simple configuration file for xinetd
#
# Some defaults, and include /etc/xinetd.d/
defaults
{
# Please note that you need a log_type line to be able to use log_on_success
# and log_on_failure. The default is the following :
# log_type = SYSLOG daemon info
instances = 60
log_type = SYSLOG authpriv
log_on_success = HOST PID
log_on_failure = HOST
cps = 25 30
}