The early warning system also delivers messages like “Let me describe how PMS feels and let you know when it’s here and how we can both avoid a blowout over something small” and “Tears are good for me and do not signal that you’re a bad person or should fix something. Just hang out and make some mild sounds of support.”

In the absence of port forwarding, Relaying may work well enough to get devices connected and synced, but will perform poorly in comparison to a direct connection.

Communication in Syncthing works both ways. Therefore if you set up port forwards for one device, other devices will be able to connect to it even when they are behind a NAT network or firewall.