i have two callmanagers, publisher and subscriber and everything works fine except failover to the subscriber once the publisher goes offline. If i shutdown the callmanager service in the subscriber, IP communicators re-registers with the subcriber but all the other phones dont. I am thinking it's something to do with DNS. The phones shows the callmanager names (not IP addresses) in their configuration and they can't resolve the subsriber name to IP. I have configured the callmanagers names in DNS server but no success. i can ping the names from my laptop and everything else a DNS should do works well from a PC. I had to change the services URLs to publisher IP address instead of names because of the same problem. Do cisco IP phones knows how to query a DNS or they just take the IP address of the DNS server and don't know what to do with it? or is it a bug on CCM 5.1.3?