Cannot update snom320 with linux firmware from webserver

On the page “software update” on the snom I pressed the load button to upgrade the linux firmware pointed by the URL which is my webserver.
This works fine !
For one phone is OK to do this in such a way but if you have hundreds phones it should be done automatically. I configured the dhcpd.conf where I point to my webserver and the snom320.html file. In the last file
I put a line which point to the .bin file of the linux firmware (as written in the mass deployment docs )
I restarted the service dhcpd and then I cycled the power of the snom.
No update took place. With the sniffer I saw that the snom has no permission to access the files although it is possible to write and read to and from that directory.
When I sniffed during the load command from the snom I saw that it uses certificates for trusting.

Questions:

  1. Does anyone faced this problem also ?
  2. Is there an acceptable solution for this problem ?
  3. Is it possible to initiate a remote Load command from the Asterisk server to the snom ? ( it looks like as if the load command is initiated from the snom itself )

Thanks in advance !

Kind regards.