[ibr-dtn] Send a message to multiple recipients at a time

Hello dear IBR-DTN authors,

I was unable to find any man pages, documentation or HOW-TOs on IBR-DTN, so the only place for asking my stupid questions is this mailing list, sorry.

Here are my questions.

1. Is it possible to send a message to multiple recipients at a time, I mean something like multicast or group messages, in order to save bandwidth?

2. Changelog states that both reactive and proactive fragmentation are supported. How does IBR-DTN choose which fragmentation type to be used?

3. Does Bittorrent DHT discovery and routing need (any) nodes to be connected to the Internet? If yes, is it possible to setup a DHT server in the Intranet, which is isolated from the Internet, and make IBR-DTN use it?

Best regards, Sergey Sireskin