Extension Mobility Roaming Across Clusters Overview
Extension Mobility Roaming Across Clusters gives users the ability to roam across multiple cluster and make or receive calls even when the user's home cluster is down. This feature leverages the Intercluster Lookup Service (ILS) to replicate Extension Mobility users' directory numbers across all the clusters.
When a user logs in to a roaming cluster, their phone registers to the roaming cluster using the directory number. Unlike Extension Mobility Cross Cluster (EMCC), where the phone from the visiting cluster registers to the home cluster, the roaming feature allows the user to maintain their registration in whichever cluster they are visiting.
To deploy this feature, you must do the following:
Set up an ILS network - ILS is used to synchronize directory number across the clusters.
For details on configuring ILS, see the Configure Intercluster Lookup Service chapter in the System Configuration Guide for Cisco Unified communications Manager at https://www.cisco.com/c/en/us/support/unified-communications/unified-communications-manager-callmanager/products-installation-and-configuration-guides-list.html
Set up a uniform dial plan - you require a uniform dial plan across the ILS network.
To set up a dial plan, see Configure the Dial Plan chapter in the System Configuration Guide for Cisco Unified Communications Manager at https://www.cisco.com/c/en/us/support/unified-communications/unified-communications-manager-callmanager/products-installation-and-configuration-guides-list.html
Device profile and user information must be synced in all the clusters.
Configure Extension Mobility.
Configure Roaming access to your Extension Mobility users.
Super User Synchronization Tool - to synchronize the superuser information across the clusters.