Having your Cisco CallManager Publisher Failover to a Subscriber

Cisco doesn't have very good documentation when it comes to publisher to subscriber failover. If you're looking to have your VoiceGateway failover to a subscriber with the ability not only to dial out but continue to recieve incoming calls your Gateway config should have a preference value, example.

dial-peer voice 20 voip
incoming called-number .
destination-pattern 3...
preference 1 <---Add
progress_ind setup enable 3
session target ipv4:10.1.24.24 <-----assumimg this is the Publisher's ip address
dtmf-relay h245-alphanumeric
codec g711ulaw
no vad

!
dial-peer voice 21 voip
incoming called-number .
destination-pattern 3...
preference 2 <---Add, higher value than that of the PUB
progress_ind setup enable 3
session target ipv4:10.1.24.25 <----assuming this is the Subscriber's s ip addess
dtmf-relay h245-alphanumeric
codec g711ulaw
no vad