thank you very much for your help.
"priority-queue out"command was inserted by "auto qos voip cisco-phone".
about trusting - "mls qos trust dscp" equals to "trust to all frames", even to PC frames. I do want to trust only to cisco-phone frames.
I will try to run "auto qos voip cisco-phone" on the other port.
and will sniff, yeah.
well still no success
"auto qos voip cisco-phone" on other side did not help
I sniffed the traffic from my port. I see phone send DSCP EF, PC - DSCP 0. that is ok
and I couldn't find CoS metrics in wireshark dump...
any thoughts, please?
Difficult issue. It may be the phone or even the model. Suggest trying the same test with different phones. Possibly once with the same type then again with a different model. Best tested with phones on the same switch with auto qos be applied to all interfaces involved. (You should be doing that anyway).
You could try different ports on the switch.
Finally, in the absence of getting any other indication as to what's going on and although the interfaces look clean it may be a good idea to try testing with the phone connected directly to the switch and not via in house cabling. There may be the off chance the house cabling performance degrades at higher data rates.
If all else is inconclusive and it can't be isolated to the phone type, infrastructure, configuration then a CCO case may be in order. If I think of anything else I'll let you know.
shame on me. it was a storm control unicast.
it drops packets... not only traps...
delete it. and everything is ok now.
thanks a lot :)