Ubuntu using BBR

UbuntuCongestionControlBBR

1.  Check if Ubuntu Linux Kernel version is 4.9
    ```bash
    $ uname -r
    ```
2. If not, follow the link http://www.yourownlinux.com/2016/12/how-to-install-linux-kernel-4-9-0-in-linux.html instructions to update your Ubuntu Linux Kernel to 4.9
3. Check again the kernel version, make sure again kernel version is 4.9
    ```bash
    $ uname -r
    ```
4. Then confirm the bbr modules is included...
    ```bash
    $ ls -a /lib/modules/$(uname -r)/kernel/net/ipv4 | grep bbr
    tcp_bbr.ko
    ```
5. Grep to see the congestion control currently using in Ubuntu, for me, my default is using cubic
    ```bash
    $ cat /proc/sys/net/ipv4/tcp_congestion_control
    cubic
    ```
6. Change the setting of tcp_congestion_control by echo, i did that in root
    ```bash
    $ sudo -i
    $ echo "bbr" /proc/sys/net/ipv4/tcp_congestion_control
    $ cat /proc/sys/net/ipv4/tcp_congestion_control
    bbr
    ```
7. You are now using bbr congestion control