RTT/RTO calc seriously flawed
Opened 19 months ago
Last modified 18 months ago
#2641newdefect
RTT/RTO calc seriously flawed
Reported by:joggerOwned by:zzz Priority: major Milestone: undecided Component: router/transport Version: 0.9.42 Keywords:
Cc:
Parent Tickets:
Sensitive: no
Description
The RTO/RTT calc is based on state.getLifetime(), which uses _startedOn. In case of NO_BW the waiting time adds to rtt instead of starting a measurement at start of actual transmission. Critical in my eyes as used for router steering including ACKing.
Can easily be seen from /peers where many reliable peers up for hours show high rtt/rto. This is self enforcing, as higher rtt mutually slows down ACKing on both ends. Also more significant after #2505 which forces the current send window to fill up completely, then completely using it up, possibly adding more than 1 sec to the rtt of the following messages.