The origins of HTTP were essentially ‘sessionless’. This meant that with a server always listening on Port 80, a client could request one URL at a time, in response to which the server would return the page in question directly to the client’s port number. This included the CGI-scripts’ FORM data. But as the early Internet evolved, Web-sites started to become ‘session-aware’. I explained this to my friends in the past as follows:
The client connects to the assigned port number 80 on the server, and requests a session, which causes the server to start listening on another port number, this forming a ‘session socket’. The one listening on port 80 was the ‘server socket’. The server’s session socket was dedicated to one client and to one session.
My friends did not acknowledge this description of how TCP works, I think mainly, because I did not use the right terminology. What I had referred to as a ‘session socket’, is officially termed a “Web-Socket” in the case of HTTP. It turns out that with an Apache server, many sub-processes can bear these Web-Sockets. They don’t exclusively exist in order to output Web-pages at a faster rate, in response to individual requests made by the clients, to the process still listening on port 80.
One fact to know about my site, is that for such purposes as viewing this blog, the use of Web-Sockets is required. In the case of certain other sections of my site, such as http://dirkmittler.homeip.net/GallIndex.htm, the use of Web-Sockets is not required, because those Web-pages exist mainly in a sessionless way – they can be fetched one at a time without error.
Certain proxy-servers will not allow a Web-Socket to get forwarded. These are logically also proxies which don’t allow SSL connections to be forwarded, because the encrypted SSL data is also sent via Web-Sockets or their equivalent. If you are connecting to the Internet via such a proxy, I’m afraid you won’t be able to navigate my blog correctly. I apologize for this, but there is little I can do about that. I think that you should still be able to fetch a single posting of mine, that comes up through a search engine.
(Edit: ) This may also apply if you’re trying to connect to my IPv6 address, because my IPv6 is being provided by a Teredo proxy, which might have just assigned reduced privileges to my client: