Disabling Vodafone autoprovisioning on Snom 821

11 03 2015

I bought a nearly new Snom IP phone on eBay, but it was getting autoprovisioned as a Vodafone device.   I wanted to use it as a SIP phone on another provider’s network, so needed to get rid of this.

I’ll try to write down the steps I followed, but I tried quite a few things so there may be inaccuracies.

Basically this phone tries three ways to autoprovision itself:

1. Redirection – it goes to a host run by Snom, is redirected to a Vodafone host and autoprovisions from there.

2. PnP – I think this is where it multicasts for a configuration server.

3. DHCP – where it receives details of the configuraiton server from DHCP options it receives with its IP address.

Redirection is the first one it tries by default, so you need to stop this happening. Snom say on their forums that they can’t do this for Vodafone devices, which must be a legal thing between them and Vodafone, because they are able to do it for Snom phones that are auto-provisioned on other providers.  In the latter case a simple request on the forums with the phone’s MAC address appears to be sufficient.

What I Think I Did:

This is what I think i did, but I’m not 100% sure it is accurate.

1. Download the Snom 821 firmware and OpenTFTP server (or Pumpkin if you prefer) and follow the instructions for re-flashing the device.  You can get these on Snom’s website.  Basically hold down the phone’s # key while applying power and keep it held down.  Select option 2 to re-flash and you then put an IP address on the phone, and tell it where the TFTP server is.  Plug a cable between your PC running the TFTP server and the phone and it downloads.

2. At this stage, keep it off the network – ideally just plugged into your PC via a direct cable.  Wait for it to start looking for a DHCP address and press the X key.  You will be able to set the language, and manual IP address at this stage.

3. Once that’s done, it reboots again.  Set the time zone and so on.

4. Now open a browser and browse to the IP address you gave it.  There should be no logon required.  if there is, you may need to do a reset (the # key procedure and then option 1) and then set the IP address manually again (step 2 above)

5. Once in the web user interface, click “Advanced” on the left menu.  Then click the “Update” tab on the right.  Change the Update Policy to be “Never Update. Do not load settings”.   This turns off auto-provisioning and only loads settings stored in the phone itself.   Apply and save this.

6. Now configure your SIP provider using the “Identity” link on the left bar and you should be good to go.

How the Redirect Works:

When the phone boots it tries to autoprovision based on the provisioning order.  If you look in the (very long) config file you will find this line:

provisioning_order!: redirection:stop pnp:stop dhcp:stop tr69:stop

This tells the phone to try redirection first and stop if it gets redirected.  Otherwise it carries on to try the other methods listed.

When it tries redirection the phone goes to this URL:  http://provisioning.snom.com/snom821/snom821.htm

It gets the following back in return:

# Redirect all phones to the php script 
setting_server$: http://provisioning.snom.com/snom821/snom821.php?mac={mac}

This tells the phone to retrieve the snom821.php page appending a variable called “mac”.  The phone replaces the {mac} part with its own MAC address (found on the base of the unit).   You can do this in a browser – browse to the URL:  http://provisioning.snom.com/snom821/snom821.php?mac=0004135337BE

This page now returns:

setting_server: https://ipcglobalconfig.vodafone.com/redirect/snom?mac={mac}

And if you replace the {mac} on this URL as well with your own, you will get

setting_server$: https://cs.vodafone-ip.de:22160/snom/getConfig.xml?mac=$mac

This appears to be telling the phone to get an XML file frm the cs.vodafone-ip.de server on port 22160.  If you again put your MAC address in and stick the above URL into a browser you will probably get a ‘page not found’ because (presumably) your MAC address is no longer configured to be allowed onto Vodafone’s system.




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