I suggest you use hard-coded channel IDs for something like that. I am doing that for Windward 2 myself. The world is made up of "maps", where each map is a 512x512 playable area. The player can travel from one map to another, and each map has a "position" in the global world that's an integer-based Vector2. I convert that to a single UInt16, and use that as the channel ID -- so as the players moves to another map, the same logic running on all clients ensures that they all end up in the same place on the TNet server.