<i>(2) There is no good solution for end-to-end transit that copes with the ugliness of endpoint networks.</i><p>Yes. That&#x27;s why the camera in the parent article calls home. The vendor says it does that so the phone app can find the camera.  If the camera and app can establish an Internet connection with each other, they communicate without going through the vendor&#x27;s servers. That&#x27;s the &quot;P2P&quot; feature.  If not, they communicate by sending video and audio through the vendor&#x27;s servers.<p>This is insecure, of course. But it&#x27;s the only way to establish phone to device communications without setup problems.<p>Skype has a similar architecture, except they don&#x27;t even try for a true P2P connection any more.