You'll just need to configure dial-peers to point calls between the two devices. There is no need to register anything.
On the CME it should look something like this,
Inbound dial-peer:
dial-peer voice 1 voip
incoming called-number
session protocol sipv2
dtmf-relay rtp-nte
codec g711ulaw
no vad
Outbound dial-peer:
dial-peer voice 2 voip
destination-pattern 9T
session protocol sipv2
session target ipv4:
dtmf-relay rtp-nte
codec g711ulaw
no vad
You'll need to configure a translation rule to strip off the 9 either on the CME or CUBE.
Similar dial-peers will need to be configured on the CUBE.
-Felipe
