how to config the tftpdhpa server in the ubuntu using for remote tftp client 'p' and 'r' command

1. sudo apt-get install tftpd-hpa

2. vim etc/default/tftpd-hpa

TFTP_USERNAME="tftp"
#TFTP_DIRECTORY="/var/lib/tftpboot"
#TFTP_DIRECTORY="/root/rt5350/RT288x_SDK/source/images"
TFTP_DIRECTORY="/root/rt5350"
TFTP_ADDRESS="0.0.0.0:69"
TFTP_OPTIONS="--secure --create --listen --verbose"

 3. so, we can using remote tftp client sent command test it like following:

         ralink is tftp-hpa client                             ubuntu is tftp-hpa server

a.   put the ralinke file "test.bin" to ubuntu

command: tftp -p -l test.bin -r name.bin 10.10.10.152

b.   get the ubuntu file "test.bin" to ralink

command: tftp -g -r test.bin -l name.bin 10.10.10.152