Adding 5 digit extensions

[gavinr98]

I have a question. Currently our CUCM is configured for 4 digit extensions. We are opening up a new office and the 4 digit ext #'s are going to start with 0. Since we use 0 for the operator, we would like to use 5 (20XXX) digits and not 4. How can this be done in CUCM without affecting the 4 digit ext that we are currently using.

[Nithin Eluvathingal]

The best option is to avoid conflict dial plans. Can you kindly share the 4 digit block which you are using at present. Whats does that mean by 4 digit starting with 0?

2.12.0.0

[Roger Kallberg · Accepted solution]

My recommendation would be to keep 4 digits for the new office, to not get a variable dial plan length as that is in general not good, and then change the first digit from 0 to something else with translation rules/patterns.

[gavinr98]

Thanks for the replies, I was able to talk them into keeping the 4 digit extension and just translate the 4 digits to something else.

[Aziz.S.Q]

Hi Gavinr98,

I have the same scenario and i did this to solve it:

Create Partition: (4digit) , (5digit)

Create Calling Search Space: (4digit_to_5digit) add the Partition (5digit), (5digit_to_4digit) add the Partition (4digit)

4 digit = XXXX ,  Create Translation Patterns (*1.XXXX),    add Calling Search Space (4digit_to_5digit), add Calling party Prefix Digits for outgoing calls  (*2), add called Party Transform Mask (XXXX)

5 digit = XXXXX , Create Translation Patterns (*2.XXXXX),   add Calling Search Space (5digit_to_4digit), add Calling party Prefix Digits for outgoing calls  (*1), add called Party Transform Mask (XXXXX)

Note. if there is delay in the calling you need to change the timing T.302 you can find it in System>Service Parameter configuration>(your publisher server, under callmanager service) change it from (15000 to 10000) this will change the calling time for the digit from 15 second to 10 second 

Note. test and apply this configuration in two IP phone only assign the Calling Search Space and check.

[Roger Kallberg]

As mentioned it is a bad and not recommended option to create a dial plan that is variable in length as that will introduce delay in calling. Reducing the T302 timer is not a fix, it is a work around or a band aid fix at the most. Any administrator should by any account do their very best to not willingly create this situation.

[Aziz.S.Q]

According to your opinion, Can you tell us the best solution? if we must apply 4 digits and 5 digits as mentioned in this senior.

[Roger Kallberg]

That would be as per my first response to this post. Ie change out the start of the number to not start with a zero and keep it at four digits in length.

[Aziz.S.Q]

But as mentioned they must have 4 digits and 5 digits and should enable call between them.

[Roger Kallberg]

This would lead to a variable number length and ultimately will give you a delay in calling due to interdigit timeout. If you anyway want to have it is just a matter of configuration in CM to facilitate the calling to both 4 and 5 digit extensions. No rocket science directly.

[Elliot Dierksen]

Adding on to what @Roger Kallberg said, the important thing in dial plan (IMHO) is to keep as many digits on the right lined up as possible. If the DID range is 012X then have the DN's 512X (or whatever non 0 or 9 leading digit). It becomes a nightmare if DID 0123 is DN 2345 and DID 0124 is DN 3456.