The Branch Visiting User survivability feature is a resiliency feature that automatically assigns a Branch Session Manager to a user at a visiting location and provides local survivability during a WAN outage. With this feature, you do not need to manually administer a Branch Session Manager or change the existing Branch Session Manager with the local Branch Session Manager for the visiting user.
Important:
You cannot enable the Branch Visiting User option until you upgrade the Session Manager and Branch Session Manager instances to release 8.1.3 or later.
If the Session Manager or Branch Session Manager software release is earlier than 8.1.3, you can still enable the feature when the Session Manager or Branch Session Manager is in Maintenance Mode. However, you cannot provision a Session Manager or Branch Session Manager to Accept New Service or Deny New Service state from Maintenance Mode if the Branch Visiting User feature is enabled and the Session Manager or Branch Session Manager software is earlier than 8.1.3.
Figure : 1. Branch Visiting User sample configuration
Before you configure a Session Manager or Branch Session Manager to enable the Branch Visiting User option, you must:
Administer the Branch Session Manager with the correct branch location on the SIP Entities web page.
Administer all possible IP Address Patterns to the location of the Branch Session Manager.
A visiting user’s IP address gets mapped to a location based on the IP address to location mappings administered in the Session Manager. The Branch Session Manager with the matching administered location gets assigned to the user.
Enable Dial Plan Transparency for all the branch and core locations. Visiting users cannot receive or make calls to the core and other branches if Dial Plan Transparency feature is not enabled.
Note:
Branch Visiting User is only supported on Branch Session Managers survivability servers. IP Office survivable branches (formerly known as B5800) do not support the Branch Visiting User feature.
The calling and device features available to a visiting user depends on the user’s administered Communication Manager with respect to the Survivable Remote Server (SRS) of the visiting branch and the state of the branch network when the user arrives.
A Branch Session Manager with the Branch Visiting User option enabled operates during a WAN failure in the following scenarios:
Sunny day arrival scenario: When a visiting user arrives at the branch in a sunny day state and a WAN failure occurs, the user administered with the same Communication Manager as that of the branch SRS will have the same rainy day feature functionality as their home branch. If the visiting user is not administered on the parent Communication Manager of the visiting branch SRS, then limited feature functionality, that is non-Communication Manager feature behavior is available to the visiting user.
Rainy day arrival scenario: All feature functionality as in sunny day state is available to the visiting user based on the user’s administered Communication Manager. Only intra-branch incoming calls can be received by the visiting user irrespective of the Communication Manager administered.
Place consistent dial plans across the Communication Manager and Session Manager instances in the enterprise to provide transparent call capabilities between the following: