Stressing video call with UDP traffic

In this experiment we are making a video call from MACBOOK (192.168.0.11) to DELL computer (192.168.0.10) using the following topology:

DELL computer has no video camera attached, so the video traffic is one way from MAC to DELL computer, that is 192.168.0.11 to 192.168.0.10

Normal conditions - no UDP traffic

In normal conditions, the ping between computers is about 0.870ms, where the MOS ranges from 4.6 - 4.9 which translates to excellent. The video has no major defects, however it's not perfect, but I suspect it to be more Linphone issue as supposed to network. Below is a screenshot of DELL computer where we can see a video window, running ping command in the left bottom corner and Linphone metrics running in the background on the right hand side of the screen.

UDP traffic generator

We are using NetScanTools suite with Packet Flooder that generate UDP packets to port 5060 (linphone), of fixed size 5000 bytes with randomized data. The number of threads is one and there is no delay between packets. The bandwidth utilization is measured by the software, please see screenshot below:

Test results

As expected the quality of voice and video degrades. The MOS is now between 2.0 - 3.0 which is v

very bad, yet Video lags a lot, but doesn't disappear. I should make a video to demonstrate the lagging.