a peer can publish any number of streams. each stream on a peer needs a unique name so the desired stream can be selected by a publisher.
for P2P streaming, each peer has its own stream namespace. a subscriber selects a stream by name from a specific peer ID.
I have a few more questions if you will.
1. Is it ok to reuse a pubish name?. Example, i have a software that publish a stream to a user with a stream name "streamA". Then i save the streamID that im getting and when the user is logged from another place he pulls his streamID from my DataBase and connects to this stream. And this is done for all my users. They all publish with a stream name "streamA" and then connect to it with their unique streamID. Is there a problem with that?
2. If the user has published a video stream from the browser and now i save his streamID to my database and the user has not closed his browser for a few days, would the streamID be still alive and he will be able to connect to it?
by "streamID" i assume you mean "peer ID".
1. yes. each peer's publishing stream namespace is separate.
2. yes, provided the connection to the RTMFP server (example, Codename Cirrus) is still up.