Mapping old numbers to new extensions in Unity version 5.0

Unanswered Question
May 17th, 2010

Hi, Just wondering if anyone has any ideas on how I can achieve this.

We have a site that is moving over to Cisco from an old PBX.

Currently calls come into the main number, route to a message and the caller can enter the 3 digit extension to be put through

to the person they are trying to reach OR they can go through to the receptionist at the site. The site have not been using their DDI range.

This will now change and the DDI range will come into use. (all current phone ext will change to the last 5 digits of the ddi range.

eg 200 will be come 23234

201 will be come 23235 and so on.

Does any one know how I can implement Unity so that calls come in to the main number in call manager, forwards to call to unity,

unity responds with a greeting, the caller can enter the old extension number (as clients know these numbers).

These old numbers would be mapped to the new extensions and then the call would be routed to the phone.

Any ideas gratefully received


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David Hailey Mon, 05/17/2010 - 05:45

If it won't cause overlap within your dial plan (and I suspect it likely would) then the only real way to do this is to assign the 3-digit (or 5-digit) extension as an alternate extension for each subscriber.  The other method would be to set the transfer option for each subscriber to the 3-digit extension and then translate in CUCM to each individual subscriber.  There are other things involved here to make that work and both get ugly.  I don't like either, personally.  I think you're asking for problems there.

I understand your desire to let the customer use the numbers they know but it's probably best to fully implement the new DID schema and go with it.  The best way to do that is with COBRAS.  You could use COBRAS to export all of the user data.  Then use the COBRAS data viewer to map the user's new extension to their alias.  Once you've done that, you re-import the user data into Unity and everything is kept intact (greetings, etc) and the 5-digit extensions are kept in use.  Again, you'll have to determine if the 3 and 5 digit combo causes overlap in Unity.  If it does then it's a no-no as Unity, unlike Unity Connection, does not have the concept of multiple partitions and CSS (i.e., multi-tenant dial plan).  If it doesn't cause overlap for you then you could use COBRAS to quickly switch all extensions over to 5-digit then use the Bulk Import/Bulk Edit tool to add the 3-digit extension as an Alternate Extension for each user.  Again, I'd be careful here...but you know what number ranges you're dealing with and I don't.


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rob.huffman Mon, 05/17/2010 - 06:04

Hi Dominic,

I really agree with Hailey on this one (+5 points Hailey). If you keep the "old"

numbers active then people never learn the "new" DID numbers and you are stuck

with this legacy config for good. It's better in my experience to make the clean break

if you can get customer buy-in. Send out notices where applicable to let people (clients

& Users) know about the upcoming changes

A couple of added ideas here;

1. Can you work with your provider to get the whole DID bank so 200 would become 23200

and 201 would become 23201. This would make things far easier to remember.

2. If you could get the matching DID's then you could put a custom greeting in place

that lets clients know the new numbering plan. "you have reached XYZ company please

note that our numbers have changed, to connect with the person you are calling please add

"23" to the beginning of all old numbers.For example if you are calling extension 201 please dial

23201. Thank-You for your patience in this matter"




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