Usually the SSH package supports HTTP(S) proxies and this should be sufficient to overcome most known proxies.
However, there are existing very difficult cases, where the proxy environment can not be properly recognized, is hidden from third party software or the target servers are behind reverse proxies.
For such difficult cases the software contains Non-SSH solution called “Rescue mode”.
If you can establish HTML5 connection, then you can be sure this software will help you to establish native socket connections through Websocket (in modern browsers such as Firefox, Chrome, Opera, and IE10) or XHR (in IE6-IE9).
Be careful, as some proxies allow Websocket/XHR traffic only via HTTPS layer, you will then need to use the HTTPS address instead of HTTP.
If proxy does not ask for proxy authentication and you can access pages via browser:
If proxy requests proxy authentication and you can access pages via browser:
Next Section: Enforce the use of web portal to connect to the server