McDewey

C H A P T E R 2 Planning the Installation • Topology Options, on page 3 • Installation Methods, on page 6 • Requirements and Limitations, on page 14 • Licensing Requirements, on page 23 • Required Installation Information, on page 27 • Export Restricted and Export Unrestricted Software, on page 32 Topology Options This section provides an overview of the system topology and describes the relationship between the types of nodes in the topology. Clusters Clusters provide a mechanism for distributing call processing, presence status, and database replication across multiple servers for scalability and redundancy. They provide transparent sharing of resources and features, and enable system scalability. A cluster comprises a set of Unified Communications Manager nodes and/or IM and Presence nodes that run compatible software versions. If you are deploying the IM and Presence Service, you must decide before you begin the installation whether you want a Standard Deployment (IM and Presence Service on Unified Communications Manager) or an IM and Presence Centralized Cluster Deployment. Both deployment options require sizing the IM and Presence Service cluster(s) for all presence users across all telephony clusters in the deployment. Installation Guide for Cisco Unified Communications Manager and the IM and Presence Service, Release 15 and SUs 3