Hi Aman,
I may not have explained this too well :)
First thing to remember here is that the config changes I am referring to are all on CCM not on Unity.
Let's say the DN in question is 5555
**Remove DN 5555 from all phones first;
Then do this from the Route Plan Report on CCM
Deleting Unassigned Directory Numbers
This section describes how to delete an unassigned directory number from the route plan report. Directory numbers get configured and removed in the Directory Number Configuration window of Cisco CallManager Administration. When a directory number gets removed from a device or a phone gets deleted, the directory number still exists in the Cisco CallManager database. To delete the directory number from the database, use the Route Plan Report window.
Procedure
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Step 1 Choose Route Plan > Route Plan Report.
The Route Plan Report window displays. Use the three drop-down list boxes to specify a route plan report that lists all unassigned DNs.
Step 2 Three ways exist to delete directory numbers:
a. Click the directory number that you want to delete **5555. When the Directory Number Configuration window displays, click Delete.
b. Check the check box next to the directory number that you want to delete. Click Delete Selected.
c. To delete all found unassigned directory numbers, click Delete all Found Items.
A warning message verifies that you want to delete the directory number.
Step 3 To delete the directory number, click OK. To cancel the delete request, click Cancel.
Once you have completed this process add the DN 5555 back to the phone again (check Call Forward All CSS and all other CSS's to make sure they don't reference the Voicemail Pilot #) and try again.
Hope this helps!
Rob
