This is an updated demo of mesh delivery. It demonstrates how a message can securely be delivered across 3 hops to reach a recipient, as well as how the acknowledgement can be delivered through mesh, following a different path.
Although these devices are sitting next to one another, you can see how the mesh cache works, how messages can be delivered to powered-off devices, and how message routes are planned on the fly and re-planned upon each hop as better information becomes available closer to the destination.
You can read more about the ChatterBox project at chatters.io.
ChatterBox is a mesh-capable LoRa messaging system that does not use internet, cell service, or any kind of service. Instead, messages are delivered through the air, either directly to the other ChatterBox, or can hop across several ChatterBoxes to reach their destination (theoretical limit of 89 hops). The longest single-hop distance I've tested so far (with different antennas than shown here) is 7+ miles. So, you could imagine the distance between the green and pink ChatterBox could be over 20 miles, and the test should produce the same result.