> [...] I am running OpenVMS 8.3, TCP/IP version -> v5.6

   As usual, showing actual commands with their actual output can be
more informative than vague descriptions or interpretations.

      tcpip show version
      ssh "-V"

> $ ftp sshftp.clientaddress.com 22

   You're apparently trying to use a plain FTP client to connect to an
SSH/SFTP server, which is unlikely to work.  You might start by trying
something like:

      sftp sshftp.clientaddress.com

(22 is the default port for SSH/SFTP, so you shouldn't need to specify
it (when you use the SFTP command).)