On Mon, Mar 30, 2020 at 08:19:01PM -0400, Anthony de Boer via talk wrote:
Might be interesting to do some traffic analysis and find out what it actually does.
Most folk are behind a NAT device of some description or other, purporting to only allow outbound connections. But it turns out that if at least one end is behind a really cheap NAT device, it's possible to trick it into thinking an inbound connection is outbound and get a session going. See Wikipedia on NAT Traversal and Hole Punching. Linux and BSD NAT implementations are too smart to fall for this, though, and denizens of this list might just have a leaning toward Linux devices.
There's a chance it would fall back to going via a public server if it can't open traversal between a pair of endpoints.
They document it here: https://jami.net/establishing-peer-to-peer-connections-with-jami/ Seems if possible they do direct, using upnp to request a port if needed and possible, otherwise they use TURN relay servers. -- Len Sorensen