Cassandra clustering provides redundant storage of SIP device data on instances of Session Manager. Starting from Avaya Aura® Release 8.0, Cassandra clustering is enabled permanently.

If you use an Avaya Aura® Device Services cluster, you must configure one or more data centers on System Manager. Cassandra data distribution uses the data center settings to identify the Session Manager instances that are within the same data center. Every Session Manager instance that is paired with Avaya Aura® Device Services must be a part of a data center. Session Manager instances that are not paired with Avaya Aura® Device Services can optionally be a part of data center. Session Manager instances should be assigned to data center based on the system topology. The best redundancy is obtained when two or more Session Managers are assigned to each data center.