Topic Last Modified: 2011-03-24

Microsoft Lync Server 2010 creates and uses an Address Book Service to supply clients with these features:

• Global Address List derived from Active Directory which provides contacts and attributes of contacts
  
  
• Distribution List Expansion for groups and contact membership in groups
  
  
• Phone Number normalization from a local format into the RFC 3966/ITU E.164 format
  
  

The Address Book Service (ABS) along with the Address Book Web Query (ABWQ), service all client types in Lync Server 2010. The ABS further enhances the performance of the infrastructure by contacting Active Directory (AD DS) at scheduled intervals to collect and update information stored in the ABS databases. The databases (Rtcab and Rtcab1) are stored as part of the databases deployed on either an Enterprise or Standard Edition Front End for the operation of the Front End, similar to information managed and maintained for presence information.

The Address Book Service and the Address Book Web Query perform similar functions, but in different ways. The ABS queries and downloads information from AD DS to be maintained in either a full download of contact information, delta files, or compact delta files. By maintaining the three types of download extracts, a new client can receive the full download and then receive either delta files or compact delta files, based on current need of the client.

Distribution List Expansion is a feature inherent to the way that contacts are stored in the ABS database files or the ABWQ. With the ABS files, the contact is associated with the groups and members of the groups. Group information is available to the client through the updated ABS files. ABWQ will directly query AD DS in the event a client asks for group membership of a client and return the group membership after the information is retrieved from AD DS.

For a fully functional communications system involving telephony, normalizing phone numbers into a usable format – regardless of where the client is – is a critical feature. If a user is making a voice call to another person on a public switched telephone network (PSTN), the phone number of the other person may be in a format that may not work without being reformatted to conventions that are accepted on the PSTN. For example, the user calls the other contact at the number that is listed for them. The number listed for the contact is from AD DS, which does not perform any phone number normalization. The number might be in the form of 555-1010. Phone number normalization will convert the local form 555-1010 to +14255551010. Normalization occurs when ABS reads the information from AD DS and normalizes it, then stores the normalized form in the address book file and index databases – RTCab and RTCab1.

What’s New, What’s Changed in Lync Server 2010 Address Book Services

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