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For the 7 targets in South Africa the 25%/median/75% before 2016 and after are ~294/300/306ms and 327/345/356ms.
Looking in more detail at the ping responses each hour we see a sudden step
and in more detail
The first step occurred between 08:00am and 09:00am Jan 14th, the second step between 07:00am and 08:00am Jan 16th (both times are GMT).
Traceroute
The route measured 19:00 hrs 1/28/2020 PST from SLAC to South Africa goes East across the US via Chicago, Washinton to London and thence S. Africa:
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