Anonymous calls (where the Caller ID has been withheld, normally by prefixing 141 to your number) can be blocked on your snom phone by using the directory.
From the web interface of your phone, select Directory on the left hand side of the screen. Then enter the following in to the Add or Entry section:
- Name: Withheld
- Number: email@example.com
- Contact Type: Deny List
- Outgoing Identity: Active
Click the Add/Edit button to save the entry. Any calls that presented with a withheld CLI will go to voicemail (if enabled on the extension, or dropped to an unavailable tone if Voicemail is not enabled).
The snom can also support CLIR and CLIP and we are awaiting technical information on how to integrate this within our hosted PBX offering.
This video will help walk you through this process. You can pause and rewind the video as necessary, and use it along with the notes below.