Assume that you deploy a Microsoft Lync Server 2010 environment that has a Survivable Branch Appliance that runs Microsoft Lync Server 2010 components. You also deploy a Microsoft Exchange Server 2010 Unified Messaging (UM) in this environment. Then, the Lync Server 2010 Front-End service on the Survivable Branch Appliance queries Active Directory Domain Services (AD DS) for the UM dial plan object. In this situation, there is too much LDAP traffic across the WAN.
Note The Lync Server 2010 Front-End service on both the Survivable Branch Appliance and the Front-End server queries for the UM dial plan object every 10 minutes by using an LDAP query.
To resolve this issue, install the following cumulative update:
2737915 Description of the cumulative update for Lync Server 2010: October 2012
After you install this cumulative update, the LDAP query will run every hour instead of every 10 minutes.
For more information about the Survivable Branch Appliance in Lync Server 2010, go to the following Microsoft website: