nivik3: Excuse my ignorance but what Direct Connection?
Direct Connection is a way for games to connect on a peer to peer basis, without requiring a server.
Requesting a Server ID does actually need a NAT punchthrough server (which can avoid some issues connecting using an IP address), but that only facilitates the initial connection.
After starting a new game, the host can open the menu in character creation and then the Connection Menu (after loading a save, this can be opened from the in-game menu or the diamond icon on top of the mini-map, in the keyboard UI). With Direct Connections enabled, the host can copy a 'Server ID' to the clipboard, then send it to the other player via chat, email, etc, or use their IP address. The other person would click on Join from the main menu, click the Direct Connection button and paste in either the Server ID or IP address and click Accept to join.