In this scenario, during a WAN outage, the features and functionality available to a visiting user depends on the Communication Manager administered to the visiting user.
User administered on the parent Communication Manager
Features: Branch Session Manager provides the same rainy day feature functionality to the visiting user as the user would have at its home branch. Complete Session Manager or Communication Manager feature functionality is available from the Survivable Remote Server (SRS) of the visiting branch.
Device functionality: Branch Session Manager provides all device settings, buttons, and contacts. Users cannot change or save contacts. User cannot store the device settings.
Contacts are available to the visiting user during a WAN outage from the device cache.
Calling capabilities: User can receive and make outbound calls to locations connected to core and users in the same branch through Dial Plan Transparency feature. Users cannot receive incoming calls from branches that are isolated and failed over to local Branch Session Manager.
User not administered on the parent Communication Manager
Features: Branch Session Manager provides limited feature functionality. Non-Communication Manager feature behavior, which includes basic calling, emergency calls, hold, resume, transfer, and conference are available based on the endpoint type. Subscriptions will not be available. Endpoint operates in non-AST mode.
Device functionality: All device settings, buttons, contacts available to the user if cached by the device. Feature buttons are not functional except for call appearances. User cannot change or save contacts when at any isolated branch. User cannot store device settings at any Branch Session Manager.
Calling capabilities: User can receive and make outbound calls to locations connected to the core and users in the same branch through Dial Plan Transparency feature. User can make outbound calls through the local SRS or PSTN trunk. This functionality is only available when consistent dial plans are in place across all the Communication Manager and Session Manager instances in the enterprise.
