wget --no-check-certificate https://github.com/teddysun/across/raw/master/bbr.sh
chmod +x bbr.sh
./bbr.sh

• This script has been fully tested on VPS instances from Vultr.
• When the script detects that the VPS virtualization type is OpenVZ,
  it will prompt an error and automatically exit the installation.
• Some providers (such as DigitalOcean) may require you to first configure the VPS
  to support a custom kernel before the grub2 configuration can take effect.
• If the script finishes running and after reboot you find the system will not boot, open the
  VNC in the VPS control panel backend. If it hangs at the grub boot screen, manually select the kernel.
• Since it uses the latest system kernel, it is best not to install it in a production environment to avoid unpredictable consequences.

If you are using an OpenVZ VPS

wget --no-check-certificate https://raw.githubusercontent.com/mmmwhy/LKL_BBR/master/lkl/install.sh && bash install.sh

• LKL requires ldd version 2.14 or above.
  Based on my testing so far, if you do not want to bother with troubleshooting, I recommend installing CentOS7,
  Debian8, or Ubuntu16 directly.
• The installation package only supports 64-bit systems.
• By default, port forwarding covers ports 1000-19999
  and can be used directly with this site’s panel one-click script.
• Only applicable to openvz

What is QUIC

Because establishing a TCP protocol connection is relatively costly, the number of handshakes required when establishing a connection can be reduced through TCP Fast Open (TCP
Fast
Open). However, this technology is currently used less often.

Unlike TCP, the UDP protocol is connectionless. After the client sends out a UDP packet, it can only “assume” that the packet has been received by the server. The advantage of this is that there is no need to confirm packets at the network transport layer, but the problem is that in order to ensure reliable data transmission, the application layer protocol must handle confirmation of packet delivery itself.

At this point, the QUIC protocol comes into play. The QUIC protocol can complete the creation of a connection within 1 to 2 packets (depending on whether the server being connected to is new or known).

Why disable it

As everyone knows, under the current state of the domestic Internet, UDP has become increasingly less ideal, so overseas games all need to use UDP proxy technology to achieve smooth performance.

Google’s servers, such as Google Search, YouTube videos, etc., all have
QUIC services deployed. This means that when you use a Chromium-based browser with QUIC
enabled to access Google websites, it will try to use
QUIC to transmit data. If it just so happens that your local ISP discriminates against the
UDP protocol and then aggressively throttles or drops packets, your speed will be painfully bad.

How to disable it

First, open your Chromium-based browser and enter the following in the address bar:

chrome://flags/#enable-quic