About the nature of MUC

Hi all,

I am using Openfire and Smack to do my final year project (FYP). But I wonder how MUC works:

  1. how MUC relays messges to the group users? send one by one or multicast?

  2. what is the maximum number of users allowed in a group? or , is MUC scalable to 10k+ group users?

I did search but no matches found

If the two questions are clear, I guess I can do my FYP better.

Please excuse my poor eng and the silly questions. Any help are very welcome. Thanks