Network fairness changes and what they mean

Sepherosa Ziehau makes commits almost daily to DragonFly’s network infrastructure, but I have a hard time quantifying it into Digest posts in part because it’s often very technical.  His most recent commits come with an explanation, however.  He has done plenty of work to improve overall transmission speeds in DragonFly, and now he’s working on ‘fairness’.  Fair, in this case, means ensuring that packet transmitting and receiving happen without either one monopolizing the connection.  In real world terms, this translates to much more constant speeds.  His recent commit details what he’s doing and some numbers to prove it.

Remember I said he’s improved speeds?  Note that in his example, he’s reaching stable peaks of 981 Mbps.  This is on a line that I assume theoretically maxes out at 1000.