Cisco Systems 5.x When Numbering Plans Overlap

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Networking Guide for Cisco Unity Release 5.x (With Microsoft Exchange)
OL-13844-01
Chapter 2 Digital Networking
Digital Networking Concepts and Definitions
Figure 2-2 No Overlapping Extensions
If the numbering plans for each location do not overlap, setting up alternate extensions is optional
because they are simply a convenience for subscribers. However, if you do not set up alternate
extensions, be sure to tell subscribers to use the extension instead of the full phone number when
addressing messages to subscribers who are associated with another location.
Note that alternate extensions have other purposes beyond their use in Digital Networking, such as
handling multiple line appearances on subscriber phones. Subscribers can have up to nine alternate
extensions. For more information, see the “Specifying Subscriber Alternate Extension Settings” section
in the “Setting Up Features That Are Controlled by Subscriber or Subscriber Template Settings” chapter
of the System Administration Guide for Cisco Unity, available at
http://www.cisco.com/en/US/products/sw/voicesw/ps2237/prod_maintenance_guides_list.html.
When Numbering Plans Overlap
Assume that subscriber extensions on Unity 3 in Figure 2-3 overlap with extensions in dialing domain A.
To allow subscribers who are associated with Unity 3 to use the phone to address messages to subscribers
in dialing domain A, and vice versa, you have the following choices:
• Instruct subscribers to enter one number that consists of the primary location Dial ID of the
destination Cisco Unity server and the extension of the recipient.
• Set up alternate extensions for each subscriber account. For each subscriber, enter a number for the
alternate extension that is the same as the full phone number for the subscriber. In this way, when
subscribers log on to Cisco Unity to send messages, the number they enter when addressing
messages is the same number that they use when calling.
• Enable the Include Locations in Searches setting. When this setting is enabled, subscribers can
address a message in two steps: they first select a location (by spelling the location name or entering
a Dial ID) and then spell the recipient name.
When a subscriber addresses a message, Cisco Unity searches for a matching extension on the local
Cisco Unity server first. If a match is found, Cisco Unity ends the search and never looks for a matching
extension at another location. Therefore, if a local subscriber and a subscriber on another Cisco Unity
server have the same extension, Cisco Unity will find only the subscriber on the local Cisco Unity server.
However, when one of the options described above is set up, subscribers on the local server will be able
to address messages to subscribers on other Cisco Unity servers.
Global directory
69671
Unity 1 Phone system 2
Unity 2
Kelly
Ext 4060
alt ext 456 4060
Phone system 1
Chris