Zoran:
In default, peer-vnc pre-built release package run in TURN style, that means all VNC traffic will go through a central peer-vnc server in cloud. And, currently the central server has only limited capabilities like bandwidth and cpu/mem size. Maybe, when lots of people were using peer-vnc, you can get DOS like connect failure.
But, peer-vnc service can run in STUN/P2P style as well, that means all VNC traffic will go through from your web browser to your VNC server directly, instead of central peer-vnc server.
To run peer-vnc in STUN style, I am developing a customized web browser based on Chrome. Hopefully, I can release the web browser in one or two weeks.
Best regards
Tom