I've had a DGL-4100 for a few months now, and until today, the GameFuel Automatic Uplink Speed feature always worked: whenever I would reboot my router, it would test the line for a little while, and Measured Uplink Speed would then show a sensible number.
As of today, it no longer works. After rebooting, the router tells me it's measuring my line, but when it finally lets me into the web UI, the GameFuel section shows this:
Measured Uplink Speed : Not Estimated
The log contains lines that say "Estimating speed of WAN interface" for each reboot, but in most cases there is no obvious followup to that message. I've tried this several times now, with only one exception: Once, the log message was followed by another one six seconds later that said "Rate estimation aborted as measurements failed to converge". Even that cryptic message is absent in most cases.
I'd like to know the following:
1. How does the router do its rate estimates?
2. Under what circumstances can an estimate fail?
3. What exactly does "rate estimation aborted as measurements failed to converge" mean?
4. When rate estimation doesn't complete, why does no explanation get logged at all most of the time?