The following procedure is used to configure a SIP URI dial plan required for integration between Lync Online and Exchange Online UM:
1. Log on to the Office 365 Portal.
2. On the main page, click the Admin tab at the top, and then select Exchange from the drop-down menu to open the Exchange Admin Center.
3. On the left side, click Unified messaging, and then click on UM dial plans at the top.
4. At the UM dial plans page, click on the plus symbol.
5. The New UM dial plan window appears, as shown in Figure 22.10. Enter the name of the new dial plan, and the number of digits that will be used.