The hub is a "centralized" (shared, anyway) database used for presence and connection setup signalling. It can be any PouchDB database accessible by both peers; a design doc will be installed. Once the connection is established, database requests are exchanged directly between peers.
Status: -This part isn't really so much implemented…yet! When it is, you will be able to delegate access to a database accessible locally, to any peer anywhere!
+ share a databaseTo fully connect with peers, you may need some browser settings or pre-release versions and unfortunately, data connections between Chrome and Firefox are not interoperable yet either. See the Chrome / Firefox / Interop notes on WebRTC.org for some deets.
Also: peers don't tend to do a good job of cleaning themselves up either. We may need to implement something of a heartbeat and toss/ignore stale peers. (…but *carefully* so as not to totally prevent slow gossip-type meshy networks, built using interreplicating PeerPouch instances as the hubs themselves, from springing up!)