Hi Kotaro!
Never tried that. Do you have so many issues regards audio?
Guess regards the number of participants it might be worth to know if you want to run the MCU in sd/nHd
or as a 2-/3-x cluster with additional audio only ports.
There are ways to generate sip audio and also video traffic if you want to test that. A consultant with some
sip knowledge will be able to help you there if you do not get a better answer.