Best way is to set up a subscription server for the phones to register to. When phone boots it calls the web page of the subscription server programmed in the 46xxsettings.txt file and passed ext, ip, mac, and set type. Makes a good starting point for push application.
I use Tomcat and JSP with PostgreSQL running on an old Win2K machine. You can also run a re-subscribe to validate which phones are still active.
See the LAN admin guide and programmers guide. I have general process document if you need guidance.