Hello,
I would like to get a better understanding of how the traffic WPT.org traffic RTT setting works and what I need to consider during my analyzes.
AFAIK WPT.org does use the dummynet solution to
a) shape the bw and
b) the delay option to influence the RTT.
Therefore I have to believe that the RTT mentioned inside the connectivity.ini files for the different connections is something I need to consider to add on top of the additional network traffic latency introduced by the real network and all kind of other included devices right?
If this is right I would need to calculate the real RTT as follow:
real RTT = RTT - delay.
A good way to measure the RTT is to use a tcp dump and lookup the initial tcp handshake.
If i do so for the russia/moscow agent with the Connection “DSL RTT=50ms” i do get the following values:
49ms = 96ms - 50ms
I did test en.wikipedia.org (91.198.174.192) from the Moscow Agent (188.120.233.22) which does show an RTT via the Traceroute of 44ms.
This fits very well into my assumption, still i wanted to ask if this is the correct way of thinking.
Thanks
Christian