You should have 4 config files ready to go when you plug in a new USB device See: http://ohnosec.org/drupal/node/49 Good practice would be to disconnect from the network before making changes to your node. Actually, stopping asterisk and then restarting it is probably the best way to do it. If asterisk thinks (for whatever reason) that the COR is active on the new USB device, it will key up the network and it will stay that way until it times out. 73 Ken