Definitions for Shared Line Across Sites

Many of the terms used for the Shared Line Across Sites feature have a number of different meanings depending on the context. To help remove some ambiguity in the procedures documented in this section, please review the following definitions in the context of the Shared Line Across Sites feature:

  • Directory Number (DN) - This number can be assigned to a user and can be dialed. It may be composed of an extension prefix and/or a site location code and/or extension, but the DN is the final form of the internal dialable number. The DN is not the E.164 number, although they may coincide.
  • DN Inventory - A list of DNs configured in VOSS-4-UC that can then be used in a line configuration. The DN inventory resides only in VOSS-4-UC and is not pushed to Cisco Unified Communications Manager. DNs may also be used as feature pilot numbers (for example, Hunt Pilot or Call Pickup patterns). When used as a service number, the DN is marked as unavailable and it cannot be used in a line configuration. DN inventory is configured at the Site or Customer hierarchy level. However, to configure DN inventory at a customer hierarchy, the customer dial plan must be configured not to use site location codes (“flat dial plan”).
  • E.164 Number - The globally routable phone number that includes country code and country-specific format. This number is used for offnet Public Switched Telephone Network (PSTN) calls.
  • E.164 Inventory - A list of E.164 numbers configured at a site hierarchy. This list only resides in VOSS-4-UC and is not pushed to Cisco Unified Communications Manager.
  • Line or Line Relation - The line configured from menu item Subscriber Management > Lines which is pushed to Cisco Unified Communications Manager. A line is also pushed to Cisco Unified Communications Manager when it is referenced in a phone, extension mobility profile, or single number reach profile and doesn’t already exists on the Cisco Unified Communications Manager. On Cisco Unified Communications Manager, a line corresponds with the items under Call Routing > Directory Number. It is also called a “line relation” because this is the technical term for the construct within VOSS-4-UC.
  • Line Appearance - A line appearance is the assignment of a line to a phone. One line can have many line appearances. If a line has more than one line appearance, it is considered a shared line.
  • Class of Service (CoS) - This term refers to a Calling Search Space (CSS) that is specifically used to define call routing and feature processing for a line or a phone. Refer to Class of Service for Shared Line Across Sites for more information.
  • SLC-based Dial Plan - A site location code (SLC)-based dial plan is one that uses unique, site-specific dialable location codes that are embedded in the DN along with the extension. For example, the default Type 1 through Type 3 Cisco dial plans are SLC-based. Only the Type 4 dial plan is not SLC-based; Type 4 dial plan is commonly referred to as a “flat” dial plan because DNs are the actual extensions. This distinction between types of dial plans is important, because to support the Shared Line Across Sites feature, where devices at different sites can share a line that supports intra/intersite dialing from every site, an SLC would not allow a line to span multiple sites (because multiple sites can’t have the same SLC). The Shared Line Across Sites feature requires the customer to deploy a non-SLC based dial plan.
  • DNR - Directory Number Routing allows an administrator to make their DN inventory inter- and intra-site routable by adding the necessary translation patterns on Cisco Unified Communications Manager when deploying a non-SLC-based dial plan. Normally, for the SLC-based dial plans, because each site requires a unique SLC, these translation patterns can automatically be deployed. This is not the case for non-SLC (flat) dial plans. In this case, DNR instances can be created when DN inventory is added to make these internally routable.
  • E.164 Associations - Allow the customer’s DNs to be reachable from the PSTN network (DDI routing). The Administrator creates an E.164 (PSTN)-to-DN (internal extensions) association to provide the DDI mapping.