Installation Guides › Implementation Guide › Configuration Considerations › Multiple Data Centers › Multiple Data Center Use Cases › Policy Server Communicating Across a Data Center
Policy Server Communicating Across a Data Center
If all components cannot be in the same data center, we recommend at least collocating Policy Servers and user stores in the same data center.
The following diagram illustrates:
- Applications in multiple data centers.
- Data center 1 only containing an Agent and Policy Server. The Policy Server only communicates across the wide area network to perform LDAP writes to the master user store in data center 2.
Important! We do not recommend configuring a Policy Server to communicate across the wide area network to perform LDAP reads and writes.
- All data centers:
- sharing a common view into the policy store through a master/replicated policy store.
- using a centralized replicated session store to enable single sign–on between all applications.
- Data centers 2 and 3 using their own master/consumer user stores.
Important! For more information about multi–mastered LDAP user store support limitations, see the Policy Server Release Notes.

More information:
Policy Server to Policy Store Communication
Master Policy Store
All Components in One Data Center