Am I using the correct hardware

First let me start by saying what I have for Service provider and equipment.

Unlimitel account iAx2

From MODEM I have a ALPHASHEILD going into my Motorola VT2442 Router 192.168.15.1

PAP2T plugs into the Router with IP 192.168.15.6

ANd Asterisk Now, FreePBX 2.5.1.5 with IP 192.168.15.7

I have been trying to get this working for weeks and would creatly appreciate some help, maybe the PAP2T is not the appropriate device, Please help.