Makes sense, thanks! I'm not sure what not using the DHT entails, does that mean you can't discover content? That can't be it, so how does that happen? Is it just gossip?
Basically the nodes of the swarm (around 100 at most) gossip events to each other. That is also how they learn about the presence of the other nodes. They try to stay connected as well as the network topology allows.
Then when you want some bulk data via bitswap they just ask their current peers. Either the emitter of the data is a current peer, then it obviously has it. Or eventually one of your peers will replicate the data, and then you will get it with some delay.
The latter happens frequently if a part of the swarm is behind a NAT. You have some delay, but eventually everybody gets all events.
