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AD/Unity overlapping dialplan question

A customer has a large enterprise and is in the midst of organizing their dialplan.

They would like to add sites to their existing CallManager 4.1.3 / Unity 4.2.1 environment but have an issue with the new sites having overlapping digits at some of these sites. This can be managed in CallManager with partitions but in Unity obviously there is no way to have multiple users with the same extensions.

So, with that said, here is the question: Can a new Unity server be built into the existing AD if it is NOT networked with the pre-existing unity environment and have overlapping extensions. I can?t think of a reason this would be an issue but I would like some validation.



Re: AD/Unity overlapping dialplan question

Hi -

This is possible, but you will need to configure your Unity servers. See this section from the Cisco link -

"When Dial Plans Overlap

When dial plans overlap across locations, you have the following options:

- Instruct subscribers to enter a 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. With alternate extensions, subscribers address messages by using the same number that they use when calling.

- Enable the setting Include Locations in Searches. When this setting is enabled, subscribers address a message in two steps: they first dial the location Dial ID and then dial the extension when prompted. See Table 7-1 on page 7-3 for more information.

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. With one of the above options, subscribers on the local server can address messages to subscribers on other Cisco Unity servers." Also you might want to read the section labelled "Dialing Domains Shield Against Overlapping Dial Plans" and put each Unity server in its own Dialing domain. One caveat is that messages sent by callers on one Unity to subscribers on the other Unity will come from the Unity_Servername mailbox. Voice messages will not show the subscriber's name - called identified subscriber messaging.

Hope this helps!


Cisco Employee

Re: AD/Unity overlapping dialplan question

Actually, you can even have the Unity servers networked together by keeping them grouped in seperate Dialing Domains. Of course, the networking features between the servers will obviously be limited. You can read more about the role of Dialing Domains in the Unity Networking Guide...

Re: AD/Unity overlapping dialplan question

I basically tell the customer this is the easiest way:

4 digit extensions at the phone that CAN be overlapping. (PT's, CSS's, and Translations take care of this)

In Unity, we use 7digit mailboxes. The Site Code + 4digit extension. If the customer never plans to grow larger than 80 sites, 2 digit site code and 4 digit extension.

In CCM, create a voicemail profile for each site with the site so when the call rolls into Unity from that site, it will pre-pend the digits to create a 6 or 7 digit subscriber ID.

It is confusing at first for the subscriber, but what don't they cry about when they get a new phone and voicemail?? :) (jokes!)

If you want set up something different, buy more Unity servers and network them. The digits CAN overlap, just not at the server.

Unity Server 1

John Doe extension 5555

Unity Server 2

Jane Doe Extension 5555

The directories are linked through (1) Active Directory, directory handlers will work then.

But if someone dials into Unity 1 and expects to enter in 5555 and ring Jane Doe on Unity 2, it does not work that way.

Hope this helps!