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Cisco VOIP phone extension number change

Hi All,


I need to do the following on two voip phones:


A voip phone has an extension of 1371- This needs to be changed to 8918 and other settings need to be put in place (similar to existing phones lines) and there is an existing phone using the number 8918 and this needs to be changed to 8989 and other settings need to be put in place (similar to existing phones lines). 

Cisco call manager solution is being used. I can pull up the existing two numbers from the "DIRECTORY NUMBER" option underneath "CALL ROUTING", but i am not sure if i need to delete the entry for 8918 and then recreate a new one ? Also i am not sure of the steps to do this.. The Cisco documentation is not specific of such extension number swapping , renaming etc. Please guide.


Thanks in advance.


Cisco Employee

Re: Cisco VOIP phone extension number change

Hey vinayak-nayak,


Just to verify:

  • Phone 1 currently has Ext 1371 - needs to be changed to Ext 8918
  • Phone 2 currently has Ext 8918 - needs to be changed to Ext 8989
  • You are using CUCM


I would suggest the following:

  1. Create a new Directory Number (DN) for 8989
    1. [Call Routing > Directory Number > Add New]
  2. Navigate to Phone 2
    1. [Device > Phone] Click on Phone 2
  3. On the left, click on the Line you want to change (8918)
  4. Enter the new DN you want that Line key to be (8989); verify all fields are correct and then click Save and then Apply Config
  5. Now that we have removed DN 8918 from the Line key on Phone 2, open Phone 1 and change the current Line (1371) to the new one (8918) using the same process as before
  6. Now the phones should have the correct DNs associated with them

It is not required to delete the DN and then rebuild it. However, I suggest taking a look at the DN and making sure that all of the fields are accurate - specifically Calling Search Space, Call Forward and Call Pickup settings, Display (Caller ID), and Line Text Label.


Hope this helps clarify the process


Re: Cisco VOIP phone extension number change

Thanks for the quick reply Anthony. I will check and let you know.
VIP Advisor

Re: Cisco VOIP phone extension number change


You can assign 8918 to new phone and then assign 8919 to the other phone.
Once you complete the assignment, the DNs won't be mapped to the old phones
and you can verify that from call routing page. You aren't going to have a
case where the phone assigned two DNs because it was previously assigned
(not in call manager).

Then you start modifying the settings per dn

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