Hi,I have replied on your another post. You can check if it could help. http://forum.tp-link.com/showthread.php?84598-Disable-NAT-on-W9970

Hi, Can you paste the log here and we'll check why it disconnect? Please try to choose Connect manually and set idle time to 0. Check if it could auto reconnect.

Hi,if the adsl led don't even blink,it means the modem is not sync up with the ADSL line. It should be a compatibility issue between the modem and ISP line.

Hi Stuart, Are you setting IPSec VPN correctly? Is the tunnel status up on the manage page? If the status is up but the device can't negotiate,you can try to disable the firewall and try again.

Hi! If you want to disable the NAT on W9970,you can go to Wan settings--Advanced. Then uncheck the Enable NAT option. Hope this can help you.

No.It don't support 3G/4G usb dongles. Usually if the router support 3G/4G function,it will show in operation mode.