I do fully understand how the technology works. Let me explain:<p>&quot;punching holes through firewalls&quot; &lt;-- This _simply_ means that the device does a connect() call towards the clients IP:port while the client does a connect() towards the device:port at roughly the same time. You simply use the fact that a simple home router opens up a temporary rule allowing the destination:port to respond to your outgoing request. This won&#x27;t work on symmetric NAT&#x27;s for instance.<p>It&#x27;s basically a completely safe method and does not open up for anyone else to connect ...<p>(The enabled by default is as I wrote in my original post is another question. The way I read the article it seems like the core focus of the post is to say that the solution used is bad or unsafe, which with given information cannot be said).