If you’re an expat in China, you’re probably already set up with your own method of unblock sites here. If you’re just arriving, you may need a little guidance. Most of the sites that are blocked in China are social networking and blogging sites like Facebook, Youtube, and Twitter. This, you already know. Unblocking sites like these is going to require you have a proxy for Facebook in China.
What’s a proxy? A proxy is like a go-between between you and a blocked site. China’s great firewall works as any other firewall does. It detects your IP address, and when a request is made for the IP address of another site somewhere, it check it’s status to see if you two are allowed to communicate. A firewall acts as much as “big brother”, allowing or disallowing you to visit sites, as it is a protective tool from spyware and spam.
So when you make a request to view Facebook, China’s firewall sees that you have a Chinese IP address. They also see that you’ve requested the Facebook IP address, and they immediately force a time-out of this connection. Funny how a time-out happens so quickly right? It’s not a real time out, its been blocked.
So when you connect to a proxy server outside of China, you enter the site with an https connection. This means that China’s not allowed to see what you’re doing at that site. It’s much like banking and other membership sites, which you type in your login credentials so that you can see a personalized version of the site that no one else can – your membership area. So because this is a secure connection, China won’t can’t say much about it.
The the proxy analyzes the request you made. Is it for Facebook? Youtube? Twitter? Either way, it takes anything that could identify your IP address off of the site request, replaces it with its own data, and send the request off again. This way, its not you that’s sending traffic to the site, its the proxy server. Not only does your Chinese ISP only see that you’re accessing a secure server or membership like site, Facebook doesn’t know you’re coming from China. These are the essentials of anonymous surfing, how to unblock sites in China, and pretty much how a proxy for Facebook in China works.