You can check the compatibility list here. Choose your region and find the compatible modems. http://www.tp-link.com/en/support/3g-comp-list/?model=TL-MR3020

MR3420v1 is an old product and discontinued long ago. So I think tp-link will not update firmware for it.

Hi,you are using and old firmware. Maybe the folder number is limited. You can upgrade the latest firmware and check if it solved your problem....

Hi,the best way is to choose PVC 2 and set static IP. It's much easier and more stable to connect.

The IP address pool will auto change to Start IP address: 192.168.1.254 end IP address: 192.168.1.254? It's abnormal behavior. You can try to reset this device and check if it could solve the...

Hi,you need to port forward on the Archer D7. First confirm the IP address of the game device. Then open the port you need for this IP address. You can also use port triggering. Hope this could help.