You've lost connection to EA Servers Xbox 360

Sometimes when you have multiple devices--such as consoles, computers, tablets, and phones--all simultaneously on the same network, especially when trying to connect to a single game server, there's a chance that one or more players will be disconnected from the server.

This is likely due to your NAT settings preventing the server's signal  from reaching all the devices on the network. 

This can usually be solved by activating UPnP on your router, as well as making sure that all devices on the network both have UPnP support, and that it is set to active.

To ensure that your connections will be stable:

• Log into your router and enable UPnP on the router.
  • If your router does not support UPnP, you likely need to contact your router provider for information on updating your firmware for UPnP compatibility.
• Enable UPnP on any devices that are on your network and direct signals, instructions on which can likely be found through your device's manufacturer or help system, as well as in Windows
  • Note, consoles should accept UPnP automatically
• Once UPnP has been enabled on your devices and computers, restart all of your device, consoles, and products.

Once you've ensure UPnP is activated on your devices, multiple consoles and/or PCs on the same local network should now be able to all simultaneously connect.

Source: http://help.ea.com/en/article/troubleshooting-connection-issues-with-multiple-devices-on-the-same-ne...

Cheers

Basti