You can use Rebex FTP or Rebex Telnet together with Rebex.Net.Ssh.dll (part of Rebex SFTP or Rebex Secure Shell) to achieve this. To connect to an FTP or telnet server through an SSH server, use this code:

using Rebex.Net;
...

// connect to SSH server X
SshSession session = new SshSession();
session.Connect("X");
session.Authenticate(userNameForX, passwordForX);


// connect to FTP server A through SSH server X
Ftp ftp = new Ftp();
ftp.SetSocketFactory(session.ToSocketFactory()); // sets up tunneling through SSH
ftp.Connect("A");
ftp.Login(userNameForA, userNameForB);
// get the file using FTP here
...

// connect to telnet server B through SSH server X
Telnet telnet = new Telnet("B");
telnet.SetSocketFactory(session.ToSocketFactory()); // sets up tunneling through SSH
// start a Shell 
Shell shell = client.StartShell();
...

(If you prefer VB.NET, please let us know!)

Other Rebex components (SFTP, IMAP, POP3, SMTP) can also connect over an SSH session in the same way.