Inter-Site On-Net Call
----------------------

The deployment model supports multiple sites with overlapping extensions
and inter-site calling by dialing the Site Location Codes prefixed with an
inter-site prefix, and supports the following dialing capabilities:

* Inter-site dialing prefix
* Variable length extensions between sites with no post-dialing delay (PDD)
  cause by timeout

When the user dials a directory number of another user, the leaf cluster first
examines the site code, and determines if the site code is for a site on the same
cluster or another cluster. If the site is on the same cluster, the call is routed
to the correct location and delivered to the phone. If the site code is for a site
on a different cluster, routing is as described in the following section.

This call type occurs between two endpoints located on different sites.
The sites can be on a different Cisco Unified Communications Manager that belongs
to the same customer. As shown in the following figure, media traffic is between
the endpoints.

On-Net Call (Inter-Site)

|dialplan-inter-site|

+---------------+--------------------------------------------------------------+
| Usage         | * User can be located in the same or different               |
|               |   countries (sites can be in different countries and or      |
|               |   different Cisco Unified Communications Manager             |
|               |   clusters)                                                  |
|               | * Target numbering must follow the Numbering Plan            |
|               |   described in this chapter                                  |
|               | * Target number can be either DN or ISP +DN depending        |
|               |   on the enterprise internal numbering plan adopted. DN      |
|               |   can be either just Extension for flat Dial Plan or         |
|               |   SLC + Extension or ISP + SLC + Extension.                  |
|               | * Any target number can be used unless restricted by         |
|               |   Class of Service                                           |
|               | * Codec is dynamically selected based on the endpoints       |
|               |   used                                                       |
+---------------+--------------------------------------------------------------+
| Accessibility | User can perform On-Net call from any endpoint registered    |
|               | with Cisco Unified Communications Manager                    |
+---------------+--------------------------------------------------------------+
| Usage Example | Reduces costs of Inter-site and International calls by       |
|               | sharing available bandwidth with Data Network                |
+---------------+--------------------------------------------------------------+
| Default       | Available to all users                                       |
| Configuration |                                                              |
+---------------+--------------------------------------------------------------+
| Configuration | * Feature availability cannot be changed                     |
| Choices       | * Codec preferences are configuration                        |
+---------------+--------------------------------------------------------------+
| Redundancy    | Available to users without restrictions                      |
+---------------+--------------------------------------------------------------+
| Survivability | Not available to users in fallback mode                      |
+---------------+--------------------------------------------------------------+
| Endpoint      | * Cisco IP phones                                            |
| Types         | * Cisco ATA                                                  |
| Supported     | * Cisco VG                                                   |
+---------------+--------------------------------------------------------------+


+---------------+--------------------------------------------------------------+
|               | ::                                                           |
|               |                                                              |
| Examples      |    Case 1: DN = ISP+SLC+Extension                            |
|               |    Phone B (DN=8 100 2345)                                   |
|               |    Dial 8 200 6789 (for Phone C)                             |
|               |    Phone B Connected Number shows 8 200 6789                 |
|               |                                                              |
|               |    Phone C (DN=8 200 6789)                                   |
|               |    On Answer, display shows 8 100 2345 -Calling Party Number |
|               |                                                              |
|               |    Case 2: DN = SLC+Extension; Extension Prefix is used for  |
|               |    Extension dialing (for example 6)                         |
|               |    Phone A (DN=300 4040)                                     |
|               |    Dial 300 4050 (Phone B extension)                         |
|               |    Phone D Connected Number shows 300 4050                   |
|               |                                                              |
|               |    Phone D (DN=300 4050)                                     |
|               |    On Answer display shows 300 4040 -Calling Party Number    |
|               |                                                              |
|               |    Case 3: DN= Extension {Dialing with full DN}              |
|               |    Phone A (DN=40404040)                                     |
|               |    Dial 40404050 (Phone D extension)                         |
|               |    Phone A Connected Number shows 40404050                   |
|               |                                                              |
|               |    Phone D (DN=40404050)                                     |
|               |    On Answer display shows 40404040 as the Calling           |
|               |    Party Number                                              |
+---------------+--------------------------------------------------------------+


.. |dialplan-inter-site| image:: /src/images/dialplan-inter-site.png