Speed Up Your Network with Google BBR

Google’s BBR (Bottleneck Bandwidth and Round-trip propagation time) is a congestion control algorithm that can significantly improve network performance. In this post, I’ll guide you through enabling BBR on your Linux system to boost network speeds.

What is BBR?#

BBR is a TCP congestion control algorithm developed by Google that optimizes network throughput and reduces latency. Unlike traditional loss-based congestion control algorithms, BBR uses bandwidth and round-trip time measurements to build a model of the network, allowing for better utilization of available bandwidth.

Prerequisites#

Before we begin, ensure you have:

• A Linux system with root access
• A kernel version 4.9 or newer

Step 1: Check if BBR is available in your kernel#

First, let’s check if BBR is available in your system:

sudo sysctl net.ipv4.tcp_available_congestion_control

If BBR is available, you should see something like:

net.ipv4.tcp_available_congestion_control = reno cubic bbr

If BBR is not listed, you may need to load the module:

sudo modprobe tcp_bbr

Verify the module is loaded:

lsmod | grep bbr

Step 2: Configure the system to use BBR#

Now, we need to configure the system to use BBR. Create or edit the sysctl configuration file:

sudo nano /etc/sysctl.conf

Add the following lines at the end of the file:

net.core.default_qdisc = cake
net.ipv4.tcp_congestion_control = bbr

Note: The cake qdisc (queue discipline) works well with BBR. Alternatively, you can use fq if cake is not available.

Step 3: Apply the changes#

Apply the new settings:

sudo sysctl -p

Step 4: Verify BBR is enabled#

To confirm BBR is now active:

sudo sysctl net.ipv4.tcp_congestion_control

You should see:

net.ipv4.tcp_congestion_control = bbr

Benefits of Using BBR#

• Higher throughput: BBR can achieve higher network throughput compared to other congestion control algorithms.
• Lower latency: It reduces bufferbloat and maintains lower latencies.
• Better performance on lossy networks: BBR handles packet loss more efficiently than traditional algorithms.
• Improved experience: Faster downloads, smoother streaming, and better overall connection stability.

Conclusion#

By enabling Google’s BBR algorithm on your Linux system, you can significantly improve your network performance. BBR is particularly effective for high-bandwidth, high-latency connections, but it can benefit almost any network environment.

Remember that kernel updates may reset these settings, so you might need to reapply them after major system updates.