Adobe live video chat

Hello All, I’m attempting to build a live video chat application with RTMFP. I’m using Flash Media’s free development server 4.5. I have already build all the User interface components. I am ready for the next stage.
For a chat application to work users need to send and exchange messages back and forth. My question is, how do Flash players communicate with other Flash players or know their peerID? For example if you had group of 50 members i can you send a message to a specific peer? I don’t know the code or class to implement this.
I have googled around and looked on several forums but found nothing. If you prior experience or knowledge in regards to this topic it be great if you can answer me!
Thank You