sysctl net.ipv4.tcp_available_congestion_control
sysctl net.ipv4.tcp_congestion_control

EPEL (Extra Packages for Enterprise Linux) is a free and open source,
popular, community based repository project aimed at providing high
quality packages that have been developed, tested, and improved in
Fedora and made available for RHEL, CentOS, Scientific Linux and
similar Linux distributions. Most of the other repositories listed in
this article are dependent on EPEL.

To enable EPEL repository on your system, use the following commands.

# yum install epel-release
Note: On RHEL 7, you need to enable the optional and extras repositories since EPEL packages may depend on packages from these repositories.

# subscription-manager repos --enable "rhel-*-optional-rpms" --enable "rhel-*-extras-rpms"

from

https://www.tecmint.com/yum-thirdparty-repositories-for-centos-rhel/