What is the maximum number of Expressways that can be clustered?

A cluster is a group of Expressways that share configuration and information, and act as one large Expressway Local Zone1.

Clustering is used to increase the capacity and resilience of the Expressway deployment1.

The maximum number of Expressways that can be clustered is six123.

However, the capacity gain from clustering is limited to a maximum factor of four, except for Small VMs, which have no gain2.

For Small VMs, clustering is only for redundancy and not for scale2.

References := 1: Cisco Expressway Administrator Guide (X14.0) - Clustering and Peers 2: Cisco Expressway Administrator Guide (X14.0.2) - Expressway Capacity and Sizing 3: Cisco Expressway Administrator Guide (X14.3) - Expressway Capacity and Sizing