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Overlapping number ranges & Unity


Hi all,

Has anyone tried using overlapping numbers ranges (in separate partitions) in CallManager and still be able to give each extension a unique Voicemail box in Unity? We are reusing the same extension range in a number of partitions all of which require voicemail, however because Unity works by extension number, extension 2000 in partition A has the same mailbox as extension 2000 in partition B. Any nice workarounds that anyone has tried for this?

Unity version: 4.0(4)



18 Replies 18

Tommer Catlin
VIP Alumni
VIP Alumni

You can use the secondary extension in the subscribers mailbox. Depends on your dial plan also. If you had Site A in Denver with DID's of 2000-2100 and Site B with DID's in San Francisco with 2000-2100.. would need to us a dial plan. Site codes work for Unity for routing, same with CCM. But would you do is add a Secondary extension to the subscriber. So it will look like (for instance) Denver site code 303+2xxx The complete secondary extension would be 3032xxxx It would be unique and could route, Bulk Edit, I believe you can do this.

hope this helps

I'm not sure what you mean by Secondary extension in the subscribers mail box. I am facing the same issue. Are you talking about Alternete Extensions?

Sorry, Alternate ext. yes. You can use Bulk Edit to add these in the alternat ext.

Hi guys,

I found a way of being able to resuse the extensions and still have unique voicemail boxes. This is done by add a unique prefix to the extension. In my case we had multiple business tenants reusing the same extension range (2XXX) so I gave each business tenant a unique prefix (e.g. 2301 for business 1 and 2302 for business 2). The Unity mailboxes were created using the extension 23012000 for business 1 and 23022000 for business 2. I created different voicemail profiles for each business tenant (using the same voicemail pilot number). The profiles added the unique prefix to the extensions.




Thanks for this post! This solution helped us tremendously and just in time for an office that is being added this weekend. I added the extension of the phone to the "Alternate Extensions" which allows the user to remotely access their mailbox and not have to know about the "facility code" prefix. Great solution! I rated your post. Thanks.


How would you handle "dial-by-extension" from an Auto-Attendant in this scenario? I am strugling with this issue for a while, users are not happy dialing 7 digit in auto attendant when they are used to 4 digits.

I can easily do this in CUE with a aef script, but I can not figure out how to do it in (more expensive) unity.

Any ideas?

Our users aren't happy either. However, they understand why it's necessary when we explain it to them. Plus, our users know to use "facility" codes when dialing other locations. For example, a Dallas office would know to dial 365-xxxx to reach someone in Los Angeles. Since our users were already use to that concept, forcing the issue within Voicemail wasn't too bad...just a little confusing to them though. We customized a prompt for those signing in remotely to remind them to append their three digit facility code. We built Call Handlers for each location to accommodate the remote sign in.

Another thing in our favor was minimal usage of "dial-by-extension". We built our Call Handlers in a way to minimize the ability for a caller to dial-by-extension. We utilize the "dial-by-name" instead as much as possible by using Directory Handlers. We have a Directory Handler for each location to allow for calls going to the proper receptionist when pressing zero.

Yup, we customized the CallHandler for each site off the central Unity server to be:

If you know your parties extension, please enter 365 and the 4 digit extension, to dial by name, press 2 now.

We set up this script for each site, just modifying the 365 to whatever their site code.

In a large enviroment with site codes or facility codes in a centralized call processing from CallManager or Cisco, you have to have a dial plan in place to a migration path to where you want to be. It's also a big marketing campaign to get the subscribers on board. Communications and setting expatations is the only way to win cultural changes within an oraganzition.... if you don't you will just be chasing your tail from now until the end.


Just as a side note here - Unity 4.2(1) has an ES available that provides new functionality on call handlers that can automate this to a great degree - this will also be in the upcoming Unity 5.0(1) release currently in EFT as well, of course.

The short story is you can create a call handler that automatically appends or pre pends (or both I guess, though I can't imagine why you'd need that) digits that you dial while listening to a greeting in that call handler.

So for instance if you create a call handler called "Prefix 365" and callers listening to the greeting in that handler dials 1234 the actual database lookup for a match is 3651234 - if that fails then it looks up just 1234 and only if THAT fails do you get the "I'm sorry..." prompt.

This means you no longer have to tell folks to prepend digits in the greeting as you describe above.

This is only there when you apply ES 8 to 4.2(1) and you have to use bulk edit to change the prefix/postfix digits on the handlers in question since it's not exposed in the SA - however I believe it's a step in the right direction for this particular issue.

Also be aware that applying ES8 will require you rerun the failover wizard if the server is part of a primary/secondary failover pair.

So what I am trying to figure out, will Unity understand now that if an outside caller, calls into a CallHandler that has the "prepend 365" configured, the outside caller can just type in the 4 digit they want to be transferred to? Unity will prepend the 365+xxxx and transfer correctly now?


Yes, that is correct. And if no match is found on 365xxxx then it will look up just xxxx and if that fails they will hear the "I'm sorry..." prompt and the error action on the handler will be taken (which you'll probably want to change to loop back to the handler itself)

Thanks! This is very helpfull. Just to confirm; is the feature available in 4.2.1 ES27 or do I have to find ES8?

You'll have to chat with TAC - I know it's in ES8 and it's rolled up into ES40 that's still being tested but I don't know what other ES packages it may appear in - ES8 was the first verified one that had this change.

Another quick question. Using this special CH, is it possible to use it to prepend digits when the user is a message (hit ## to address by ext vs name)?

Thanks in advance.

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