For detailed instructions regarding auto provisioning Snom M900, M700 and M300 devices, please see the auto provisioning guide here.
In order to provision the firmware you must use a separate XML file with the firmware-settings as first tag (root tag). Here is the more exact procedure:
Step 1 - add a <file> tag to your main configuration file, pointing to a separate firmware provisioning file, for example:
Step 2 - create test_firmware.xml and place it on your HTTP server. Here is an example content of the test_firmware.xml file for upgrading to version 450B11: