Great Firewall of China

The Great Firewall of China is a collection of technologies, legislated and enforced by the People's Republic of China, to regulate the Internet within China. It is designed to block access to selected foreign websites and to slow down cross-border internet traffic.

The Great Firewall checks transmission control protocol (TCP) packets for prohibited keywords and prohibited content. If the keywords or content appear in the TCP packets, access will be denied. If a connection is blocked, subsequent connections from the same machine will also be blocked by the Great Firewall. The Great Firewall will analyze, filter, and manipulate the internet traffic that crosses China's borders.

Generally speaking, file transfers will only be blocked if prohibited keywords or content is found in the data. This can include any references to prohibited 3rd Party sites and services. However, there are times when the People's Republic of China will block all cross-border internet traffic, usually during censored events such as the weeks before and after June 4th, the anniversary of the Tiananmen Square Massacre.

Encrypted file transfers can also be blocked depending on the transmission protocol (FTP(S), SFTP, HTTP(S), WebDAV, etc.), the encryption type (TLS, SSL, SSH, etc.), and the encryption ciphers being used. The Great Firewall is constantly adjusting to internet traffic so it's impossible to determine exactly why a connection could be blocked. We recommend you test various transmission protocols and ciphers to determine which best meets your needs.

Our customers have reported that there are no access problems between China and Files.com when using the FTP(S) and SFTP protocols.

Using the web browser or the HTTP(S) protocol, can have access problems. This is typically due to the underlying URLs or APIs using a prohibited 3rd Party. For example, China actively redirects their user connections to Baidu instead of Google so if your Files.com site is using Google Cloud Storage, or Google Drive, as a Remote Server Mount then connections to those folders may fail when using HTTP(S).

We recommend using SFTP or FTPS for connections between China and Files.com.