IP telephony problem in a big shop | Need your help

Unanswered Question

Hello everybody,

I have an issue to solve regarding an IP telephony problem. My company will send me to France to fix this problem. But most of my knowledge are in routing and switching, I have almost no knowledge in IP telephony ( Theory only). I think the problem is not really difficult but I still need your advices to know where to start and what to do.

Futher down is a summary of the e-mails I received from the shop in France from the employees who are working there. France Telecom is the ISP.

1 e-mail:The problem is the connection between the ISDN lines provided by France Telecom and the IPBX installed by our shop.

2 e-mail:The problem isn't the physical line itself. The problem is that they ( France telecom) do not route all the numbers out to the ISDN line they installed. The number ending with 1212 get routed to the ISDN NT and that number actually works. But the rest of the number series does not get terminated in that ISDN NT. Calling those other number result in an error message being read in French. That can only come from France Telecom.

3 e-mail:We cannot solve this problem because it is not the system which has an error. Carl has been in Bordeaux and has checked the ISND line at that is working, but the number series for Bordeaux is missing in the system from France Telecom, the only existing number is 1212. The rest of the numbers are missing for French Telecom and is therefore not working. Either we have been informed of a wrong number series +33 5 34 32 12 04 to 13 or France Telecom has not delivered what they should.

4 e-mail:I checked again with France Telecom and they confirmed that everything is delivered and ok from their side.

They gave us the number series +33 5 34 32 12 04 to 13 with main number (headnumber) is +33 5 34 32 12 12 (exactly as in Paris where we are n° series from +33 1 53 25 13 70 to +33 1 53 25 13 89 with the headnumber is +33 1 53 25 13 70).

That's the reason why you find only the +33 5 34 32 12 12 arriving into the IPBX, it's because you then have to program in our IPBX the other n° we want to use (+33 5 34 32 12 04/ 05/ 06/ 07/ …10/ 13/…) within the number series granted by France Telecom.

But this can be done only by us because we installed our own IPBX.

5 e-mail:Even though the other numbers aren't programmed into the IPBX, we should still get some sort of ISDN Layer 1 activity when calling one of the other numbers (fx. the 07number). That never happens, which means the numbers are somehow impeded from France Telecom.

When we call one of the number, we get an error message in French. If the traffic was hitting the IPBX, then that couldn't happen. That speak originates from France Telecom and we have never gotten any explanation as to why it's even there.

I will really apreciate your help. Where do you think the problem comes from? Is that really France Telecom whose empeded the series number(do not route the numbers)? What should I check/do, configure?

Thanks a lot for your help to all of you.


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paolo bevilacqua Thu, 07/03/2008 - 02:51
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Hi, all this category of problems are usually understood and resolved using "debug isdn q931" and "term mon". Of course also some understanding of telephony is necessary.

It is not really necessary to travel over there to work on these problems (unless of course you want to see France, that is very understandable), just a good connection, good terminal program, etc.

Of course if you can prove the problem is actually with telco you need someone with perfect french command to talk them. Just like British, they're not very tolerant of people mistreating their language.

Hi, Thank you very much for your fast reply.

I am french so it is not a problem for me to talk with French ISP.

Could explain me what I should say to the Teleco to prove it?

Where I should expect/look at from these commands to see where the problem comes from ?

# term mon

# debug isdn q931

Thanks again for your help.

paolo bevilacqua Thu, 07/03/2008 - 03:28
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With that you see calls coming in and out.

If you do not receive calls to "your" numbers, then it's telco problem, else it's your problem.

Zin.Karzazi Thu, 07/03/2008 - 03:32
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The Commands needs to be entered on the router connected to the PSTN, then you make an inbound Call to your internal Number using your Cellphone.

You will see something like this:

Transfer Mode = Circuit

Transfer Rate = 64 kbit/s

Channel ID i = 0xA18394

Preferred, Channel 20

Progress Ind i = 0x8283 - Origination address is non-ISDN

Calling Party Number i = 0x00A3, N/A

Plan:Unknown, Type:Unknown

Called Party Number i = 0xC1, '558940'

Plan:ISDN, Type:Subscriber(local)

Where the Called Party Number is the line you should look at, this is basically the number France Telecom is passing to you.

On aura aussi besoin de la configuration de ton router (H323 or MGCP), le IPPBX que vous utilisez (Callmanager or Callmanager Express) et le nombre de canneau de ISDN (combien de e1 pri) :)


Zin.Karzazi Thu, 07/03/2008 - 04:49
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Email sent.

It would be also nice if you could post the config here, so other people could benefit from this thread.


jean-luc.decourt Thu, 07/03/2008 - 11:53
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verify in the debug trace how many digits "Orange" (france telecom) send to your PBX. Generally 4 digits are sent, but sometime 9. This depends of the telco configuration

And verify also the messages :

TX -> .....

RX <- .....


jean luc

jean-luc.decourt Fri, 07/04/2008 - 04:07
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see below an example

2409207: Jul 4 08:49:12.504: ISDN Se0/0/0:15 Q931: RX <- SETUP pd = 8 callref = 0x1BC0

Bearer Capability i = 0x8090A3

Standard = CCITT

Transfer Capability = Speech

Transfer Mode = Circuit

Transfer Rate = 64 kbit/s

Channel ID i = 0xA98396

Exclusive, Channel 22

Calling Party Number i = 0x2180, '33472965555' <= my phone number

Plan:ISDN, Type:National

Calling Party Number i = 0x2183, '.........' <= NDI appears here

Plan:ISDN, Type:National

Called Party Number i = 0x81, '.........' <= Called number appears here

Plan:ISDN, Type:Unknown

High Layer Compat i = 0x9181

Sending Complete

2409208: Jul 4 08:49:12.612: ISDN Se0/0/0:15 Q931: TX -> CALL_PROC pd = 8 callref = 0x9BC0

Channel ID i = 0xA98396

Exclusive, Channel 22

2409212: Jul 4 08:49:13.208: ISDN Se0/0/0:15 Q931: TX -> PROGRESS pd = 8 callref = 0x9BC0

Cause i = 0x87F2 - Unknown cause value

Progress Ind i = 0x8281 - Call not end-to-end ISDN, may have in-band info

2409215: Jul 4 08:49:17.765: ISDN Se0/0/0:15 Q931: TX -> PROGRESS pd = 8 callref = 0x9BC0

Cause i = 0x87F2 - Unknown cause value

Progress Ind i = 0x8281 - Call not end-to-end ISDN, may have in-band info

2409216: Jul 4 08:49:17.773: ISDN Se0/0/0:15 Q931: TX -> ALERTING pd = 8 callref = 0x9BC0

Progress Ind i = 0x8088 - In-band info or appropriate now available

2409225: Jul 4 08:49:23.177: ISDN Se0/0/0:15 Q931: TX -> CONNECT pd = 8 callref = 0x9BC0

2409227: Jul 4 08:49:23.217: ISDN Se0/0/0:15 Q931: RX <- CONNECT_ACK pd = 8 callref = 0x1BC0

2409231: Jul 4 08:49:34.713: ISDN Se0/0/0:15 Q931: TX -> DISCONNECT pd = 8 callref = 0x9BC0

Cause i = 0x8790 - Normal call clearing

2409234: Jul 4 08:49:34.897: ISDN Se0/0/0:15 Q931: RX <- RELEASE pd = 8 callref = 0x1BC0

2409235: Jul 4 08:49:34.973: ISDN Se0/0/0:15 Q931: TX -> RELEASE_COMP pd = 8 callref = 0x1BC0

callref = 0x1BC0 => received message

callref = 0x9BC0 => transmitted message

Please, post your debug's trace.


jean luc


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