Telephony, Design and HCS Dial Plan Overview
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VOSS Automate provides automation and
standardization to Unified Communications Manager and other elements 
such as IOS devices, Cisco Unity Connection, and Cisco Unified
in a repeatable way.

Bulk loaders can be employed to provision
and onboard customers. Central to this goal, the routing architecture and
associated element configuration meet in a configurable model that is used
within VOSS Automate. 

In this guide, the model is referred to as the HCS Dial Plan Model
and HCS Dial Plan or simply Dial Plan Model and Dial Plan.

.. important::

   Only the VOSS Automate Provider solution supports the HCS dialplan tools.

The main purpose of the Dial Plan Model is to create a
pre-integrated baseline configuration of Unified Communications Manager
applications. The Dial Plan Model can then be integrated into the platform
and the service provider infrastructure with minimal effort. The Dial Plan
Model configures not only the end customer equipment like Unified
Communications Manager or on-premises routers, but also the interaction
with aggregation layers using products such as Cisco Session Management
Edition, or Session Border Controller for those functions. The 
standard configurations are provided, but the service providers
must customize parts of the model for a particular environment.

For the end customers, the dial plan is designed to handle a significant
portion of the corporate dialing schemes. It includes
a standardized model on how to handle intrasite, intersite, and PSTN
calls, generally using a site + extension methodology. It also spans
advanced routing requirements of elements like central versus local
breakout for PSTN calls and also handles the different numbering
requirements across multiple countries.

The intersection point between the dial plan and VOSS Automate
comes in the definition of standard telephony services that
abstract Unified Communications Manager configurations into simpler
choices that correspond to the feature plans a service provider wants to
offer, and end customer to consume. For example, the partitions, calling
search spaces, and translation patterns are predefined based on a choice
of simple outbound, inbound, call forwarding, and time of day settings,
which in VOSS Automate are exposed as service
types. These services are combined into feature packages and templates
that define a user or lines telephony services.

Given the central role to the architecture and the provision workflow,
this document outlines the key architectural elements that define the
Dial Plan Model, the mechanics of how the model is constructed,
and the resulting service configurations in VOSS Automate.
In addition, the model can be customized to fit different
infrastructure requirements and customized service types.