Exchange Offline Address Book Update Overview

Exchange Offline Address Book Update Overview

The Hosted Exchange solution provides several enhancements to the core Microsoft Exchange product and the Hosted Exchange MPS provisioning system. These enhancements enable you to overcome the address list limitations and provision more than 1000 Global Address Lists (GAL), Address Lists (AL), and Offline Address Lists (OAL) per forest.

The current release of Microsoft Exchange Server is limited to supporting a maximum of 1000 Exchange Server Offline Address Lists per server. Because of this, it is necessary in a hosting environment to distribute OABs among several available servers rather than keeping the OABs on the same server where the hosted organization's mailboxes reside.

For this release of the Solution, the Offline Address Book Update utility must be used in combination with Active Directory Ntdsuti.exe utility in order to perform this function. You use Ntdsutil.exe to raise MaxPageSize to a value greater than the number of Offline Address Books, whenever the number of Offline Address Bools exceeds 1000.

Increasing Active Directory MaxPageSize

The technical article titled How to view and set LDAP policy in Active Directory by using Ntdsutil.exe describes how to raise MaxPageSize above its default value of 1000. This is a requirement whenever you use the OAB Resource Manager to rais the number of OABS above 1000.

OAB Resource Manager Namespace

The Exchange OAB Resource Manager provides an API that tracks and allocates available servers that can hold OABs. This API enforces the 1000 OAB per server limit. The Exchange OAB Resource Manager can track: .

• Available servers that can host Exchange OABs.
• The capacity of servers in the OAB resource pool.
• OABs that have been allocated.
• The customer organization that owns each allocated OAB