Recent TCP Enhancements

Recently (2013-2016)  there have been a number of enhancements to the Linux TCP code that potentially can have a large impact on TCP throughput. A number of these enhancements are described in this talk:

• David Miller NetDev KeyNote, Feb 2015)

The most important changes include:

• packet pacing
• dynamic TSO sizing
• TCP small queues

• BBR TCP (first available 2016 in the 4.9 kernel)

Many of these enhancements became widely available starting with RHEL/CentOS 7.2 and Debian 8.

BBR TCP is available starting in RHEL/CentOS 8.0, Debian 9, and Ubuntu 17. To run BBR TCP on a RHEL/CentOS 7.x host, try using the latest 'stable' kernel from kernel.org. The easiest way to install this kernel is to use the ELRepo kernel.