Hye,
For a gameplay, we need a switch box where 3 people can talk to each other.
However, there's one person who control's the chat. so we need a box where he can adress te output.
Example:
P1 talks to controller and controller can talk back.
P2 talks to controller and controller can talk back.
P1 and p2 can talk to each other only after controller says ok.