Apart from sharing URIs and Patterns between clusters, ILS naturally shares UDS data, including home cluster.
In the example below, only a single _cisco-uds._tcp record can exist due to a shared dns zone, however using feature group templates to control the home cluster setting means the user will be “found” and home cluster information will be relayed with the request so the client finds it’s home.
Perhaps clarify that ILS does not support Jabber contact resolution across clusters via UDS. I think there is some confusion out there about that. Jabber clients using UDS always point to their home CUCM cluster for UDS contact queries. The LDAP search function on each CUCM can be used to proxy UDS queries for contact information to LDAP.