inid IU on left power supply for outside iNid on right
as far as the iNid goes, there is only one router for the inside.
The pictures above I found off an ebay listing, On the left is an IU modem that looks like an old DSL modem with more lights and on the right is the power supply unit that actually powers an iNid with a case for Battery backup inside if needed
With your uverse voice the iNid sends the dial tone right from the iNid so there is no other inside device. The unit that will have to be place inside for power is also white and is square and it will have a battery that is for backup in case of power failure.
Edited for picture