A land use ftp server, and then log on to the target server B, using the ftp command from the ftp server download files, speed quickly, download bandwidth than upload bandwidth to be bigger
https://blog.csdn.net/df0128/article/details/45146799
https://blog.csdn.net/smooth00/article/details/88734958
Lcd can use ftp server with an account password
SSH2 Easy
Plug-in support for FTP download and upload