From Snom User Wiki
This method requires the following components:
|ONE DHCP Server per LAN |
supporting DHCP Option(s)
66 or/and 67
|Auto Provisioning Server||Configuration Files||snom VoIP phone configuration|
The DHCP Server must be configured with additional DHCP Options containing the URL of the Auto Provisioning Server to the snom VoIP phones on boot-up. The phones will then request their configuration parameters from the Auto Provisioning Server which will result in a "ready-to-use" phone setup without manual configuration.