Shared Line Across Sites
------------------------

This feature allows lines to be shared across sites, and is accomplished
by introducing the concept of an "Inventory site" in addition to the
normal real sites. The Inventory site is used to provision the shared
lines first, then the real sites make use of the shared lines by
assigning them to phones. Devices are not provisioned in the Inventory
site; they are only provisioned on the real sites.

This feature also supports Hunt Groups and Call Pickup Groups across
sites by leveraging the Inventory site to provision all of the lines to
be included in the Hunt Group or Call Pickup Group. The lines used in
Hunt Groups and Call Pickup Groups that are provisioned in the Inventory
site can span multiple real sites (in other words, they are used by
devices on the real sites). The key requirement is that all the lines to
be used by a given Hunt Group or Call Pickup Group must be configured in
the Inventory site, along with the Hunt Group and Call Pickup Group itself.

The Shared Line Across Sites deployment model is 100% backward
compatible with the previous directory number (DN) and line
configuration. Existing deployments are not impacted when the system is
upgraded, and all existing dial plan configuration procedures are
supported. The deployment configuration shown in :ref:`shared_line_across_sites_example`
is optional and is only required when sharing lines across sites.


.. tip::

   If a line is potentially shareable, we recommend that you create the line in
   the Inventory Site, even if it will not be shared across sites immediately.
   The system does not support the ability to move a line from a real site to an
   Inventory Site, so to convert a line from site-local to cross-site shared,
   the line would need to be deleted from the real site and recreated in the
   Inventory Site.