Installed kurento media server 6.6.2 on Ubuntu 16 using following link
https://doc-kurento.readthedocs.io/en/6.6.2/installation_guide.html
As seen in the image the connections are established but video is not loading as shown in the image
Demo code can be downloaded from https://doc-kurento.readthedocs.io/en/6.10.0/tutorials/node/tutorial-one2one.html
Kurento was not able to put the remote video, as the network may be behind the NAT. so one needs to add STURN/TURN links. Click here for reference