Ask HN: Are my assumptions about the Great Firewall true?

https://news.ycombinator.com/item?id=8478254

by westiseast • 12 years ago

4 2 12 years ago

news.ycombinator.com

I was wondering, out of interest, if someone more knowledgeable could explain whether my assumptions about the Great Firewall are true/false/impossible/paranoid delusions :) I live in China, and run an online business based in the UK, so I waste a lot of time dealing with The Great Firewall.

* I assume the Firewall is vindictive - if I visit a blocked website, it seems to then block any other website for a short period of time. * I assume that part of the Firewall involves 'trusted' routers or particular network points. I mean, I can connect to my VPN at home, but NEVER from a Starbucks or public wifi. * At some level, I assume that my browser is maybe infected with some virus and plays some part in choosing what to block and when. * I assume that despite using a VPN, the government probably still knows what I'm looking at. * I assume that, somewhere on a government database, I have a profile that is invoked during the Firewalls activities that says "yeah, don't worry about this guy, he only reads news and isn't involved in protest movements" or something like that.

I'm not really paranoid (!), but just realised I have a lot of assumptions about what's happening behind the scenes, but no idea whether those things are even possible. Many thanks!

auganov• 12 years ago

It somewhat matches my experience too. Generally I'd say there's 3 classes of blocking: total block (twitter, fb), rate limiting (google), and general QoS downgrade (which seems so random that it might just be the infrastructure being so bad). I really doubt any of that happens ad-hoc based on your usage profile. And yes I did notice that certain routes might not work on non China Telecom networks, but that again is probably just bad infrastructure. I always assume The Great Firewall is 80% market protectionism and 20% censorship (or rather irrational fear on the side of the govt). Wouldn't worry from a user's perspective.

tbronchain• 12 years ago

Hmm, not quite.

Here are my assumptions after spending time in China since almost 2 years now: 1- Nope, it's not vindictive. If you can't access any other website after visiting a blocked site, you maybe have a problem with you network configuration (just an assumption). 2- You cannot connect your VPN in a Starbucks because they block the ports/protocols that allows your VPN to work. Sometimes, it's also the reason why it's hard to connect to your VPN. It's also the reason why sometimes your connection may suddenly stop working (download speed drop to 0). My assumption on that is, if, randomly, they detect too much trafic through encrypted channel, they block it. 3- No, if you're not using a Chinese browser, you're probably not infected by any "virus". Although, some says QQ may include some spyware in it. I don't know much on that. 4- Your provider knows what you're looking at. Like any provider in the world. Because internet companies in China are owned by the government at more than 50%, then indirectly yes, the government potentially knows what you're doing. The truth is quite different. In reality, their system is pretty similar than prism (yes, really). When the "police" require some data, they ask the providers about the metadata. That's it. From what I've heard, they're much less organised than they seems. The real difference between Chinese gvt and others it that they don't hide doing it. Plus the censorship. 5- "I assume that, somewhere on a government database [...]", hm, probably not.

I've heard GFW had several ways to "censor" the internet: DPI and DNS poisoning mostly. Also some "random control". Also, the GFW is this kind of system able to learn and adapt itself. Apparently, if too many people try to access a foreign website, it gets blocked. There is also some crawlers looking for keywords ... Not 100% sure, it can be only guesses.

About the "QoS downgrade" @auganov was talking about, once again it's a bit different. What really happens is that the providers have a limited bandwidth to go outside of China. Biggest providers (China Telecom/Unicom) have "a lot", others have really not much, but it's still pretty limited, and when many people are connecting together, we're back in the old days of "rush hours" and slow internet. In the middle of the night, I can easily reach 5MB/s (which is about 40Mbps), through VPN.

Hope I answered your questions :) Also, if anyone knows a bit more about GFW, I'd be glad to hear about it!