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New Member

Verifying CME cgn number sent to PSTN (ISDN)

I'm tracing a caller ID issue from a CME system. What is the best way to verify what the system is sending to the PSTN as caller ID?

I used "debug voip dialpeer" and received this output (I have put X's to hide the valid called number

Nov 23 17:56:15.107: //-1/44493A6D91BF/DPM/dpMatchCore:

   Dial String=02xxxxx274, Expanded String=02xxxxx74, Calling Number=

   Timeout=FALSE, Is Incoming=FALSE, Peer Info Type=DIALPEER_INFO_SPEECH

I note that the "Calling Number" is blank. Does this say to us that the system is not sending any number out to the PSTN?

I thought at very least the system should send the primary button line number (in my case 3694) to the PSTN?

Super Bronze

Verifying CME cgn number sent to PSTN (ISDN)

Hi Tony

For an ISDN voice circuit use 'debug isdn q931'. This shows the actual signalling packets sent out to the PSTN on the ISDN.

If you see a TX--> SETUP message, it;'s the start of a call setup. This will show any called/calling numbers.

Same applies for inbound tshooting - a new call is signalled by an RX--> SETUP message, if you don't see it the call hasn't arrived (i.e. time to call the service provider).



Please rate helpful posts...

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!
New Member

Verifying CME cgn number sent to PSTN (ISDN)

Thanks Aaron! I did this command just after posting the above and note the following:

MV-C2851-CUCME#debug isdn q931

debug isdn q931 is              ON.


Nov 24 09:54:13.800: ISDN Se0/0/0:15 Q931: Applying typeplan for sw-type 0x12 is 0x0 0x1, Calling num 3694

Nov 24 09:54:13.804: ISDN Se0/0/0:15 Q931: Sending SETUP  callref = 0x0D0D callID = 0x9289 switch = primary-net5 interface = User

Nov 24 09:54:13.804: ISDN Se0/0/0:15 Q931: TX -> SETUP pd = 8  callref = 0x0D0D

        Bearer Capability i = 0x8090A3

                Standard = CCITT

                Transfer Capability = Speech

                Transfer Mode = Circuit

                Transfer Rate = 64 kbit/s

        Channel ID i = 0xA9838F

                Exclusive, Channel 15

        Progress Ind i = 0x8183 - Origination address is non-ISDN

        Calling Party Number i = 0x0180, '3694'

                Plan:ISDN, Type:Unknown

        Called Party Number i = 0x81, '02xxxxx74'

                Plan:ISDN, Type:Unknown

Nov 24 09:54:13.944: ISDN Se0/0/0:15 Q931: RX <- SETUP_ACK pd = 8  callref = 0x8D0D

        Channel ID i = 0xA9838F

                Exclusive, Channel 15

Nov 24 09:54:16.852: ISDN Se0/0/0:15 Q931: RX <- CALL_PROC pd = 8  callref = 0x8D0D

Nov 24 09:54:16.856: ISDN Se0/0/0:15 Q931: RX <- ALERTING pd = 8  callref = 0x8D0D

        Progress Ind i = 0x8488 - In-band info or appropriate now available

Nov 24 09:54:17.420: ISDN Se0/0/0:15 Q931: TX -> DISCONNECT pd = 8  callref = 0x0D0D

        Cause i = 0x8090 - Normal call clearing

Nov 24 09:54:17.484: ISDN Se0/0/0:15 Q931: RX <- RELEASE pd = 8  callref = 0x8D0D

Nov 24 09:54:17.484: ISDN Se0/0/0:15 Q931: TX -> RELEASE_COMP pd = 8  callref = 0x0D0D

So from my debugs I can see that we are sending the four digit extension as expected. I have raised a call with the Telco so I can find out what we need to send so they do not strip or replace the calling number.

Super Bronze

Verifying CME cgn number sent to PSTN (ISDN)

Hi Tony

Some pointers then:

1) You can normally only advertise out numbers that are valid DDI numbers or the main billing number for the circuit you are sending out. Is 3694 a DDI number?

2) Some SPs will expect you to do one of these:

- Set the type to 'national' (use a translation-rule/profile on the outbound voice int to do this)

- Set the number to the full national number (e.g. 020xxxx3694 or perhaps 20xxxx3694)

In general, look at what gets send inbound when you call in to this system, and try to mirror it outbound.

3) It may just be that the correct box wasn't ticked on the order form and they aren't permitting anything. Do you get a defualt/billing number, or just 'witheld' on the far end?


Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!
New Member

Verifying CME cgn number sent to PSTN (ISDN)

Thank you for verifying Aaron. I have asked the telco to tell me if I need to send the full national number, so that this is permitted, or if they will prepend the rest of the number to the beginning of the DDI. At the moment they strip the four didgits (which is the last four of the DDI) and add the full billing number. This ISDN has at least two DDI ranges and it appears each handset has a DDI too.

In prior communication between the telco and the customer (who is a general IT manager) the telco informed them that "anything we send will be permitted as caller ID". Obviously this is not the case and I couldn't see how that would be allowed anyway.

I'm currently on my first CCNP-Voice study book so this is good studying. Once I know exactly what ranges the customer has routed to their system I can plan the translation rules.

There is currently a outbound translation profile applied to the "voice-port" interface. However the translation-rules applied to the profile do not have any rule lines configured. I assume this is legacy configuration as cannot see any point in this.

New Member

Verifying CME cgn number sent to PSTN (ISDN)

To update, 

I was told that the telco needs the last 6 digits from the DDI number. I configured this but no change, so I then configured to send the full 020xxxxxxx number but the same. Each time the caller ID is the billing number. I am quite sure that the telco has configuration in place to strip what I send and replace it with the billing number, so have logged this as a fault.

I have run a debug as before, and have sent this to the telco to confirm we are in fact sending the "correct" number of digits. They keep telling me that my config is incorrect and this is why the caller ID is wrong. I'm pretty sure this is not the case. It seems no matter if it's an ISP or a Telco they all seem to shirk responsibility

My config is as follows (for reference):

voice translation-rule 3

rule 1 /^3694/ /09&/

voice translation-profile BT-ISDN-OUT

translate calling 3

translate called 4

voice-port 0/0/0:15

translation-profile incoming BT-ISDN-IN

translation-profile outgoing BT-ISDN-OUT

dial-peer voice 6 pots

corlist outgoing call-standard

description ** UK numbers **

destination-pattern 90[1-8]T

progress_ind alert enable 8

progress_ind progress enable 8

progress_ind connect enable 8

port 0/0/0:15

prefix 0

PS - I did not set this system up! And yes it is annoying to wait for the time out.

New Member

Verifying CME cgn number sent to PSTN (ISDN)

Okay, I eventually got to the bottom of this. The original order specified that we need to send seven digits as caller ID. BT will then prepend the rest. I have tested this and it works correctly.

I have used the below rule to affect this for everybody as requested, for both DDI ranges.

voice translation-rule 3

rule 1 /^36../ /409&/

rule 2 /^76../ /318&/

Thanks for your help Aaron

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