Reverse Number Lookup (RNL) with Lync server

Reverse Name Lookup in Lync Server comes into play in the following scenario's:

• when an incoming call is entering: if the calling user is in the directory as a contact / user, Lync will show the display name instead of showing the telephone number.
• when you enter a (piece of) a phone number in E.164 notation in the search field of the Lync client  (this means the international number format starting with +)

Lync looks at the following attributes to retrieve phone numbers:

• "LineURI" (Lync Management Shell) / "URI" contact attribute
• Telephone number attributes in Active Directory

Pit Falls

• If you're not using the E.164 international number format, Lync should know how to do the conversion to E.164 format of these numbers. create the rules for this in Company_Phone_Number_Normalization_Rules.txt on the Lync Server.
• Lync doesn't look directly into AD, but maintains its own copy of the AD attributes in the Offline Address Book. Make sure you force a sync first if you'ld like to have up to date information.