Hopefully You understand what i write - english is not my first language
@pepper - You wrote that you got an AVERAGE of 10mbit (download) using dsl reports - IF SQM is setup to assume a 12/2 Mbit connection (SQM set to 10200/1700 - 85% of 12/2 Mbit) however in real life, it is only getting 10/2 Mbit, then it vill not work properly once the connection is saturated.
If You use the AVERAGE result from speedtests taken during the day, then you will probably not notice any problems MOST of the time.
However if/when the bandwith drops “alot”, typically in the evening (if your ISP is overselling the bandwith) - then everything starts to suck, wife starts to get angry and children starts crying…
That is why i recommend using the WORST result from speedtests when setting up QOS - especially in “low-bandwith” scenarios. Remember to TURN OFF QOS when meassuring the bandwith, and do it at diffrent times throughout the day - also pay attention to the upload speed.
So, for fun i made some tests throtteling the bandwith to 10/2 KEEPING the (WRONG) SQM settings of 10200/1700 (85% of 12/2 mbit)
then pinged 126.96.36.199 (cloudflare) on a second PC - and got a stable baseping of 9ms
I then started to saturate the connection - and pings began to fluctuate between 9ms to 52ms and got a lot of “requests timed out” indicating that QOS was NOT working as it should anymore. I tried to open a copule of web-pages - they took ages to load.
when i set SQM appropriately to 8500/1700 (85% of 10/2), pings fluctuated between 9ms and 13 ms - and no “request timed out”, and the webpages loaded…slowly …
You Could try to set SQM to the above values, and see if that helps.
BUT as jeffsf said 12/2 is not much for 10 concurent users - a single 1080p Youtube video could use upto 5+ Mbit/s on average (Yes I know this is an oversimplification on how Youtube downloads work ) - So You are running out of bandwith very fast
oh don’t know if You have seen this video - demo starts at around 3:00