- You create a user account in Active Directory Domain Services (AD DS). Then, you set the value of the telephoneNumber attribute to have no extention. For example, you set the value of the attribution to +1xxxx1444.
- You enable the user for the use with Microsoft Lync 2013 and the Enterprise Voice feature.
- You configure a Line URI for the account, and you set it to have an extension. For example, you set the value of the msRTCSIP-Line attribution to tel:+1xxxx 1444;ext=1444.
- The user tries to set up call forwarding. To do this, the user clicks Forward Calls To at the bottom of the Lync 2013 UI.