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.