When a user searches for a contact by using the Search for a contactoption in the Add a Contactwizard in Office Communicator, Office Communicator forwards the request to the Front End Server, which queries Active Directory Domain Services (AD DS) for the latest information. Because this operation increases network traffic, you can change the limits on contact searches by end users who are adding new individuals to their contact lists. The limits you define do not apply to searches for existing clients because those queries are to the internal database. The internal database is not queried when a new contact is added because it is refreshed by the Address Book service only once per day, so it can be up to 24 hours out of date at the time of a query.

The query limits apply to all SIP clients and servers in an Active Directory forest.

To specify how client search queries are handled by Office Communications Server

  1. Open the Office Communications Server 2007 R2 snap-in.

  2. In the console tree, right-click the forest node, click Properties, and then click Global Properties.

  3. On the Searchtab, do the following:

    • In the Maximum number of rows returned to the clientbox, type a number from 1 through 1000 to specify the maximum number of results that the server returns to a client response in a new contact query. The default is 20.

    • In the Number of rows requested by the serverbox, type a number from 1 through 3000 to specify the number of results that are requested by the server in a single query. The default is 200. This number must be equal to or greater than the number you specify for the Maximum number of rows returned to the client.

    • In the Maximum number of outstanding requests per serverbox, type a number from 1 through 500 to specify the maximum number of pending requests that the server can handle before it declines additional search requests. The default is 80. This number must be equal to or greater than the number you specify for the Number of rows requested by the server, which must be equal to or greater than the number you specify for the Maximum number of rows returned to the client.