Description of Proxy connection using UTF-8 TeraTerm Pro with TTSSH2
Proxy is a technology which can be used to connect to outisde where Internet environment and LAN are separated as shown in the following

There are various types of Proxy for this purpose and UTF-8 TeraTerm Pro with TTSSH2 supports the following types of Proxy¤
HTTP Proxy requires that SSH server at the other end uses port 443 as connection accept port. Usual SSH accepts an incoming call at port 22. This is required to provide SSH connection as if it is HTTPS (HTTPS uses port 443).
To configure, select [Setup] menu, then choose [Proxy].

Then [Proxy Setup] dialog will appear. Specify the type of proxy in [Type], Hostname (or IP address) of Proxy server in [Hostname], Proxy port number in [Port number] and click [OK]. [Username] and [Password] can be used only when Proxy needs an authentication.

Now, you are ready - try to connect (if you specify HTTPS, make sure that [TCP port#] of connection dialog is set to 443....).