Sites should broadcast any name changes to all other sites. You can program using the web interface, just create a user on each system (doesn't need a phone, and you could just use your regular programming username and pass, since that user is created automatically) and point your browser (IE only) to the phone system IP of the node the user resides on. Clich the SYSTEM tab and USERS AND PHONES, choose PHONES, and edit is the pencil next to each name.