It is a fast and secure socks5 proxy designed to protect your Internet traffic. You can learn more here.
Long story short, it is a proxy that is commonly (and secretly) used in mainland China. People use it to access GFW blocked websites, such as Google, Facebook, etc. You can view a more detailed blocked website list here.

Source: https://tumutanzi.com/archives/13005
BBR ("Bottleneck Bandwidth and Round-trip propagation time") is a new congestion control algorithm developed at Google. Congestion control algorithms — running inside every computer, phone or tablet connected to a network — that decide how fast to send data. You can learn more [here](https://cloudplatform.googleblog.com/2017/07/TCP-BBR-congestion-control-come