Many users reported they sometimes have strange problems to use internet in mainland China. Especially during periods like June 4, July 1, Oct 1, or other major events, such as 人大會議.
Problems mainly include:
1. cannot access some overseas web sites, such as Google, Yahoo, banks, etc.
2. cannot send or receive email from mainland China to overseas (include HK)
3. Internet speed is very slow
4. got error messages like tcp-connection-reset, server not found, service not available, etc.
These problems are usually caused by the Great Firewall of China, which is a country-wide firewall that installed by mainland China government.
Althrough we do not access unwanted web sites or send unwanted emails, but our Great Firewall is sometimes too busy in filtering other people's communication, that may caused delay in ours.
When the delay is long enough, other "normal" servers will drop our connection, that is why we got the problem.
If you google "Great Firewall of China" or "金盾工程", you will found many interesting articles.
If you email to people in mainland China, be sure not to use any of these words .
If you want to access overseas web sites from mainland China, please read the "Efforts at breaking through" section on this web page
If you are IT professional who run mail server in mainland China, I would suggest you to get a oversea mail-relay, and then tunnel your SMTP traffic through VPN to the relay. I know this sounds stupid, but it works. If you know better method, please let us know.
Another common mis-understanding about VPN:
- althrough Great Firewall does not block VPN, sometimes VPN can be dropped because Great Firewall is too busy in filtering other people's traffic. -- VPN solved many problems, but it does not solve all.
If you want very fast and stable connection, you may consider IPLC (but very expensive).
PS: - If you are in mainland China, some links above are probably blocked.
- If you have a real urgent message that cannot get through, please use FAX.
