/mcpExtension Mobility Roaming Across Clusters Interactions and Restrictions Extension Mobility Roaming Across Clusters Interactions This section lists the interactions of the Extension Mobility Roaming across Cluster with other Cisco Unified Communications Manager Administration components. • Extension Mobility • Inter-Cluster Lookup Service (ILS) Extension Mobility Roaming Across Clusters Restrictions This section lists the restrictions of the Extension Mobility Roaming across Cluster with other Cisco Unified Communications Manager Administration components. • If the hub ILS is down, the spokes connected to it will not synchronize until the hub is back. Different Types of Extension Mobility The following table lists the different types of Extension Mobility features available in Cisco Unified Communications Manager and their differences. Table 45: Differences Between EM, EMCC, and Extension Mobility Roaming Across Cluster Extension Mobility Roaming Across Cluster Extension Mobility Cross Cluster (EMCC) Extension Mobility (EM) Allows user to roam across other clusters using own login credentials. Allows users to access their phone settings from a phone in another cluster. Allows users to temporarily access their phone settings from other phones in the same cluster. Description The roaming cluster phone registers in the roaming cluster only. The remote cluster phone registers to the user’s home cluster, accessing the settings in the home cluster. N/A When the user logs in to a phone in another cluster Multiple clusters Multiple clusters Single cluster only Intercluster Extension Mobility Roaming must be configured in all the cluster. EMCC must be configured in the home cluster and each cluster that the user visit. Single cluster only Configuration Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs 462 Receiving Calls Extension Mobility Roaming Across Clusters Interactions and Restrictions