E18 Door Phone Administrator Guide
19.4.DHCP Provisioning Configuration
Auto-provisioning URL can also be obtained using DHCP option which allows
device to send a request to a DHCP server for a specific DHCP option code. If
you wan to use Custom Option as defined by users with option code range
from 128-255), you are required to configure DHCP Custom Option on the
web interface. Path: Upgrade > Advanced > DHCP Option.
Note:
The custom Option type must be a string. The value is the URL of
TFTP server.