Changing the number that is assigned to the IPCM server from the out of the box installation
1) Log in to the Management Portal.
2) Click the System Configuration icon.
3) Click the Voice Server link.
4) Change the value for the listed feature "Server's Telephone Number:" to the number desired.
5) Click the Update button.
6) Restart the IPCM Server if the number does not work as expected.