License provisioning has always been a bit of a challenge in the Cisco Unified Communications Manager (CUCM) environment. Prior to CUCM v9.0, licensing was managed on a per-cluster basis with each cluster requiring its own license files that were tied to the media access control (MAC) address of the cluster’s publisher. This approach to license management was limiting in the fact that one cluster might have unused licenses while another cluster may be at its limit and sharing between clusters was not possible.
All of this has changed with CUCM v9.0 and the addition of the Enterprise License Manager (ELM) as part of the CUCM installation.
ELM provides enterprise wide management of user-based licenses. You can now have multiple clusters sharing the same license pool. ELM will also substitute a higher tier license for a lower tier license if the lower license pool has been exhausted and higher tier licenses are available. This provides greater flexibility in license utilization at any moment in time.
ELM comes pre-packaged along with each CUCM installation. You can choose to install ELM as a co-resident application in conjunction with CUCM, or you can install ELM on a stand-alone server. Furthermore, you can have a single ELM server managing licensing for the whole enterprise, or you can have several ELM servers controlling licensing for certain portions of your enterprise. You can install ELM on a Cisco Media Convergence Server (MCS) or as a virtual server.
Once ELM is installed, you will define product instances within ELM. A product instance will refer to the publisher of the cluster for license synchronization and management.
In addition to the standard license usage reporting capabilities, ELM also comes with a dashboard view. The dashboard view provides a single glance overview of the system from a licensing perspective. There are clickable links in the dashboard that link you to the appropriate pages in the ELM interface.
Once you define product instances (such as CUCM clusters), you will then need to determine if you have sufficient licenses for the cluster or if additional licenses are required. You can use the Add Licenses Wizard to assist with that determination.
After you have determined how many licenses are required, you can generate a license request. With the license request information in hand, you can the Cisco license registration site and paste the information in the appropriate fields. Your license files will arrive via email and you can then proceed to install the license file in the ELM server.
CUCM v9.0 ELM supports CUCM and Cisco Unity Connection licensing.
Things have further changed with CUCM v10.0. ELM has been migrated to Cisco Prime License Manager and adds support for Cisco Emergency Responder application. Cisco Prime License Manager is supported only as a virtual deployment starting with CUCM v10.0.
In summary, ELM and its successor, Cisco Prime License Manager, allow for more efficient license usage by allowing multiple clusters to share in the license pool. It also provides more comprehensive license reporting across the enterprise as well as access to a suite of license management tools for simplifying license management across an enterprise deployment.