Yes they should see the loop back . You may want to give a hard loop at the NIU , you
will need a patch cable and a adtran loop plug . Has your telco company been able to
sync up with frame relay ? Is your lmi-type matching what the carrier has set . Is your
DLCI correct ?
There are as you see several issues you can address, however just follow this list again .
1. Verify with the phone company all is ok ( ie bandwidth, DLCI, and Lmi-type )
2.Verify IOS programming interface and sub interface ( should be like this )
Router(config)#int ser0
Router(config-if)#encapsulation frame-relay
Router(config-if)#frame-relay lmi-type Cisco
Router(config-if)#no ip address
Router(config-if)#no ip directed-broadcast
Router(config-if)#no shut
router(config-if)#end
Now for the sub-interface
Router(config-if)#int ser 0.1 point-to-point
Router(config-subif)#frame-relay interface-dlci 16 IETF <----- IETF for none cisco
Router(config-subif)#ip address 192.168.1.1 255.255.255.0
Router(config-subif)#no shut
I hope this helps you out, Good Luck ! #-)