The total traffic of ftp.fau.de increased from 3.22 PB in 2018 to 3.52 PB in 2019, an unusually small increase of only 9%.

Rank	Mirror	Traffic 2019 in TB	Rank/Traffic 2018 (for comparison)
1	qtproject (Qt Toolkit)	511	2 / 445
2	kiwix (offline Wikipedia)	458	1 / 476
3	mint/iso	260	5 / 255
4	lineageos (Free and Open-Source Android distribution)	246	3 / 327
5	eclipse	162	4 / 266
6	opensuse	138	7 / 119
7	fedora	136	6 / 137
8	cdn.media.ccc.de (Talk recordings from CCC and related conferences)	120	– / 94
9	centos	117	9 / 109
10	osmc (Open Source Media Center)	112	8 / 113

The percentage of IPv6 traffic increased a tiny bit again, to 25% (0.87 PB), after 22% in 2018, 22% in 2017, 14% in 2016 and 11% in 2015.

There is little change in the Top 10 overall, with traffic volumes staying pretty much the same, only some mirrors swapped their places in the table.

Our mirror of cdn.media.ccc.de managed to reach the Traffic Top 10 again, but it was a close call. This mirror makes most of its yearly traffic at the end of December / beginning of January, when the recordings of the annual Chaos Communication Congress are put online. On the other hand, the CTAN mirror that was on rank 10 last year did not make the Top 10 this year, missing it by a few TB (106).

A notable new entry that would be on rank 11 is F-Droid, a community-maintained Android software repository only hosting free/libre software (sort of an alternative to Googles “Play Store”). We started mirroring this at the end of 2018, but only recently they added functionality that makes the clients use the mirrors more often. As a result, this mirror has seen some a lot more usage in recent months, and is likely to reach the Top 10 in 2020.