TCP Congestion Control: CUBIC vs. Google BBR

The internet isn't just about bandwidth; it's about flow control.

1. The Old King: CUBIC

Standard Linux uses CUBIC. It interprets Packet Loss as a signal to slow down. But on modern fiber, random packet loss happens without congestion.

2. The New Standard: BBR

Google developed BBR. It doesn't care about packet loss. It models the network pipe's width and RTT.

Result: Enabling BBR on a server can increase throughput by 30-40% on high-latency links.

echo "net.ipv4.tcp_congestion_control=bbr" >> /etc/sysctl.conf