What do you mean that you "lost" the menu? Is it hiding under the sofa? Did the dog eat it? We can't help if you don't type more words in your posts to describe more details.
Plug a telephone into the device. Pick up the phone. You should hear a dialtone. If so, key in ***1. Do you hear the automated voice read out the IP address? It should start with 192.168 or 10.0. Write it down. Enter it into a web browser. It should take you to the configuration page. The default username and password are both "admin".
If you can't get to that page, then my guess is that you got these devices from a service provider that has locked the devices, so you can't change any settings.
