CUCM digit analysis behaviour

Unanswered Question
Jul 13th, 2009

I have two DNs on CUCM7 system

Phone1 DN is 222

Phone2 DN is 2222

partition/Calling search space setup are all right.

the below test is performed on phone3 with DN 333

behavior 1,

press new call, heard dial tone, dial 222, then phone1 ring, which is expected, and with this method, phone2 never got chance to be dialed

behavior 2,

press 222, then press softkey "dial", phone 1 will ring, which is expected

press 2222, then press softkey "dial", phone 2 will ring

my question is, how CUCM doing digit analysis while "press 2222, then softkey dial"? is digit by digit or consider "2222" as ONE digit/string?


I have this problem too.
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Overall Rating: 4 (2 ratings)
Adrian Saavedra Mon, 07/13/2009 - 23:35

Hi friend,

The "Route Patterns" section in the following link explain how CallManager route calls and I believe it could clarify your doubts:

Please rate if helps...

Best regards!

- Adrián.

Jaime Valencia Tue, 07/14/2009 - 06:51

CUCM always does the analysis digit by digit, you can open a CUCM trace and look at this.

The behavior is different because the phone is on-hook and then you press dial button. CUCM then considers you have dialed all the digits and does not need to wait for anything else (same way as you going offhook and pressing #)

If you want to understand how it works look CUCM traces.



if this helps, please rate

study_voip Tue, 07/14/2009 - 07:50

thanks for everyone

but if I am sending "2222" and CUCM does digit by digit, it means phone 2 will never ring

but when I press 2222 then press dial, the phone 2 ring, so it can not explain CUCM is doing digit by digit

Jaime Valencia Tue, 07/14/2009 - 20:47

There already 3 explanations, what you say does not makes sense unless you're calling translation patterns or route patterns with urgent priority checked, and you said this were phones, right?

If you have 222 and 2222 all that will happen is there will be IDT when you dial 222 if you're offhook.

Simply an overlapping will happen, read the dial plan section from SRND to understand overlapping and it's effects.

When i was at TAC you have no idea how all of us hated the "any updates?" comments



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CHRIS CHARLEBOIS Wed, 07/15/2009 - 05:29

So, assuming that the urgent priority is not checked on the route pattern, there is a difference between dialing the number, then pressing dial versus picking up the handset then dialing.

Specifically, when pressing the dial button, there is no need to wait for any inter-digit timeout. Therefore, it can be thought of as going out as one block, however it appears in the trace logs. The behavior is what is important.

study_voip Wed, 07/15/2009 - 06:33


I can not agree with you.

your explanation did not explain my situation even I knew "any update" may not the prefer language as your expectation

there is no route-pattern or xlate patten at all, only 3 DNs on the system




I want to 100% understand how CUCM doing digit analysis while I am dialing "2222" ONHOOK compare OFFHOOK

use OFFHOOK method, 2222 can never be reached because CUCM doing digit by digit and as long as after 3*2s, 222 ring

use ONHOOK method, 2222 can be reached, so how CUCM doing digit analysis in this case?

looking for your reply

thanks again

Jaime Valencia Wed, 07/15/2009 - 06:46

From the CUCM SRND i instructed you to read:

Dial Plan

Avoiding Overlap of Extension Dialing

-There cannot be overlapping strings of different length. For example, a system with extensions 1000 and 10000 would force users to wait for the interdigit timeout when they dial 1000.

The behavior is explained above, and backs what i've told you.

If you really want to understand gather CUCM traces and look at them.

DA is ALWAYS done digit by digit with SCCP endpoints, only SIP endpoints with dial rules on it can send them enblock.

When you dial onhook cucm detects you never went offhook, does not provide dial tone. Therefore it already knows that when you press dial is because you've already dialed all the digits you want and immediately sends the call, the same would happen if you go offhook and press #.



if this helps, please rate

study_voip Wed, 07/15/2009 - 06:54


I don't think I am going to design two DNs like 222 and 2222

based what I read from SRND, 2222 should never be reached but it does, so a little confused how CUCM performing digit analysis.

so correct me if wrong, with ONHOOK method, CUCM would ignore the digit by digit logic, furthermore, it will ignore any urgent priorty xlate pattern/route-pattern as well. otherwise, 2222 can not be reached

one example could be

I do have 91.12222222 translation pattern (pre-dot,urgent priorirty default on CUCM6)and 911 route-pattern, with ONHOOK dialing, I should be able to dial 9112222222 without any problem, right?

thanks agian

study_voip Wed, 07/15/2009 - 07:15

regardless urgent priority or not, with ONHOOK method, I can reach both 2222 and 9112222222 (911 route pattern urgent priority checked)

so either CUCM break the digit by digit analysis rule or CUCM treat "2222" "9112222222" as single digit


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