The CUE AA receives call from the CME via a SIP dial peer. So as long as you have a dial peer that points to the IP address of the CUE , it should be reachable from POTS legs , IP legs (if you have 'voice service voip'/'allow connections ...' configured) and ephone call legs.

The dial peer should be something like this -

!

dial-peer voice 10 voip

description - calls to AA application on the CUE

destination-pattern 5000

session target ipv4:10.1.1.1 <---Ip address of CUE

session protocol sipv2

codec g711ulaw

dtmf-relay sip-notify

!

The CUE will need to have a relevant config as well - you can enable the aa application from the GUI or from the CUE cli. All it needs is a trigger number that matches what you have configured under the SIP dial peer on the CME.

Otherwise paste the configs of the CME and CUE here so we can have a look at it.