We are also changing how remote playback works for streaming personal media (that is, playback when not on the same local network as the server). The reality is that we need more resources to continue putting forth the best personal media experience, and as a result, we will no longer offer remote playback as a free feature. This—alongside the new Plex Pass pricing—will help provide those resources. This change will apply to the future release of our new Plex experience for mobile and other platforms.
The self-hosted servers use UPnP and NAT-PMP to automatically forward the port used for media streaming.
They actually also can relay. I’ve been stuck in an apartment with managed internet and no NAT or UPnP and my media streams over plex relay instead.
This is also useful for countries and communities that are double natted
Lots of people in this thread are confusing direct streaming and plex relay as the same thing