After looking at your system we can see that you mistakenly updated the PBX connection information in the problematic phone sets. The Call Continuity module sits between Asterisk and the phone sets transparently (it uses the same IP and Port that Asterisk did, so phones should not see a difference). In your case you changed some phones sets to connect to the cluster’s SIP on port 15060 (the Asterisk SIP port), but they should be connecting to port 5060 (the HAast CC module SIP port).
In the following diagram, you can see how you are moving from the top topology, to the bottom topology. This is *transparent* to phone sets – do not change their SIP configuration information. Only Asterisk SIP settings have changed (to route SIP traffic through the HAast CC module).
