From version X12.5 onwards, this guide applies only to the Cisco Expressway Series product (Expressway) and no longer applies to the Cisco VCS product (VCS). Older VCS guides on Cisco.com are still valid for the VCS versions they apply to—as specified on the title page of each guide.

The guide covers the following topics:

• Clustering Requirements

  Describes the required network environment and minimum configuration of the peer Expressways before you can cluster them.

• How to Form a Cluster

  How to form a cluster of one, add peers to a cluster, and configure cluster address mapping if necessary.

• How to Change a Cluster

  Processes like upgrading, taking peers offline, changing the primary peer, and disbanding the cluster.

• How to Connect the Expressway Cluster to Other Systems

  How to connect the cluster with external systems like Cisco TMS, other Expressways, and endpoints.

• Troubleshooting

  Guidance that may assist if the cluster is not working as expected.

• Reference

  Additional material that may be relevant to your environment.

For information about license usage and capacity with clustered systems, refer to the Expressway Administrator Guide on the Cisco Expressway Series Maintain and Operate Guides page.