Traditionally, Office Communications Server clients, such as Office Communicator 2007, have provided users with global address list information by searching a local Address Book file that the client downloaded from a shared folder on a dedicated file server. In this release, Office Communicator and Office Communicator Phone Edition continue to download and use the Address Book files that Address Book Server provides. However, Office Communications Server 2007 R2 introduces the Address Book Web Query service to provide global address list information to users of the 2007 R2 version of Microsoft Office Communicator Mobile for Windows Mobile client. By using Address Book Web Query service, Communicator Mobile for Windows Mobile clients can provide results to user search queries by sending an HTTPS query over the Internet to the Address Book Web Query service instead of downloading Address Book files onto the mobile device.

The Address Book Web Query service is automatically installed on the Web Components Server when you install Office Communications Server 2007 R2 Enterprise Edition or Standard Edition. The Address Book Web Query service is hosted by Internet Information Services (IIS) and uses Integrated Windows authentication to authenticate clients. You can view the Address Book Web Query service URL on the Web Components property page at the pool level. By default, the URL is https://<WebFarmFQDN>/GroupExpansion/<Int|Ext>/service.asmx. Clients obtain the URL for Address Book Web Query service through in-band provisioning.

In this release, Address Book Server continues to retrieve user and contact information from the RTC database to write Address Book files for Office Communicator, Office Communicator Phone Edition, and Office Communicator 2007 R2 Attendant clients to download. In addition, Address Book Server now creates an Address Book database (RTCAb) that contains a subset of user and contact information on the back-end database used by Enterprise pools and Standard Edition servers. Address Book Web Query service does not require access to the file server used for Address Book Server download files. Rather, in response to search queries from Communicator Mobile for Windows Mobile clients, the service submits queries over HTTPS directly to the RTCAb database created and maintained by Address Book Server.

Note:
When the server’s Address Book Server PartitionByOU WMI property is set to TRUE, the scope of the RTCAb search is limited to the same organizational unit (OU) as the client that submitted the search query.

In addition to generating new versions of the Address Book download files on a daily basis, Address Book Server now also updates the RTCAb database daily. To provide high availability and to achieve redundancy, the lookup table in the RTCAb database contains two partitions so that one partition can be used while the other is updated.