Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Hide Extension Number on Internal Calls

Hi Guys,

I'm deploying CUCM 8.5 in a new environment, and for some extensions the DN can't be displayed for internal calls. How can I do that on CUCM?

Thanks a lot


  • IP Telephony
Super Bronze

Hide Extension Number on Internal Calls


You can use 'calling party transformation patterns' to hide numbers.

The process is like so:

  • Create a partition (called 'transformations' for example)
  • Create a CSS (called 'calling-transformations' for example) and add the 'transformations' partition
  • In Call Routing/Transformation/Transformation Pattern, add a new pattern. Put it in the 'transformations' partition, so that it matches the DNs you want to hide. If you have lots of DNs, you may need to make lots of copies of the pattern. In the 'calling party tranformation mask' set the DN you want to display instead - for example this might be the number of the department. Alternatively, set the 'Calling Line ID Presentation' field to 'restricted' to show 'unknown number'.
  • Next, assign the new 'calling-transformations' CSS to the device pools of the phones that will RECEIVE the calls - this will probably be all device pools. Reset the phones that will receive the calls (or your test phone).


Aaron Harrison

Principal Engineer at Logicalis UK

Please rate helpful posts...

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!
This widget could not be displayed.