magicjack plus and Time Capsule 2TB

I have been using the new MagicJack Plus with my Time Capsule 2TB with no problems for 6 months. Then it stopped working. It can't connect and all that happens is the network light comes on then the telephone light comes on I get a dial tone for a few seconds then the lights go out and the sequence starts all over. I recived a new MagicJack Plus and it did the same thing so MagicJack sent me a third one still the same thing. We tried different power adapters and different ethernet ports but nothing works. I can't seem to find the MAC address or even an IP address for the MagicJack using the Airport Utility 6.3.1 with the latest firmware. I wanted to try to open ports 5060 and 5070 but apparantly you have to assign it to an IP address which I find strange. The MagicJack Plus works fine when attached to a computer via USB. Any help would be appreciated.