NewNode: Messenger that keeps working during internet outages

This is remarkably light on details.. How is identity validated when the central server is offline? How can one build routes in case of intermittent point-to-point connections?

On the other hand, FAQ says:

> At the core of both our NewNode messaging app as well as the NewNode VPN is the open-source NewNode protocol. It’s this protocol that automatically detects the optimal path for your data. If there is no wifi connection, NewNode will route your traffic through a network of connected devices.

> As long as one of the peer devices down the line has access to a functional mobile network, your device will too. This strategy bypasses the limited central server of typical messenger apps and enables higher levels of connectivity.

so this kinda sounds like if there are no "functional mobile network" anywhere (say there is a wide-area outage), then this won't work at all?