Calling party ID issue...

Unanswered Question
Jun 12th, 2007
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I'm having an issue with a local service provider and I was hoping someone could help out. The customer I'm working with wants individual extensions to be passed as the calling number for external calls. The extensions are masked with the area and exchange codes at the route level. The gateway is an MGCP gateway.

Now every time an outside local number is called it receives the main listed number as the Calling party number.

I can see, using debug isdn q931, that we are sending out the extension info and not the main listed number. However, the service provider insists that we are not sending them anything or that we are sending the main listed number.

Am I right in my assertion that the Called Part Number field of the q931 debug is the information we are sending? I personally think the service provider is full of it. But I want to make sure.



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paolo bevilacqua Tue, 06/12/2007 - 08:27
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Hi Justin,

please send the q931 trace here. If we agree, as it's likely, that is correct, you are ready to fax it to telco (if they don't use email yet :)

Just mask a digit or two if you are concerned about making the numbers visible.

jmachiggins Tue, 06/12/2007 - 08:41
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Here's a copy of the debug-


Jun 12 15:47:27.199: ISDN Se0/0/0:23 Q931: TX -> SETUP pd = 8 callref = 0x0008

Bearer Capability i = 0x8090A2

Standard = CCITT

Transfer Capability = Speech

Transfer Mode = Circuit

Transfer Rate = 64 kbit/s

Channel ID i = 0xA98397

Exclusive, Channel 23

Display i = 'Garner Sales'

Calling Party Number i = 0x0081, 'XXX7557070'

Plan:Unknown, Type:Unknown

Called Party Number i = 0xA0, '6124214'

Plan:Unknown, Type:National

Jun 12 15:47:27.595: ISDN Se0/0/0:23 Q931: RX <- CALL_PROC pd = 8 callref = 0x8008

Channel ID i = 0xA98397

Exclusive, Channel 23

Jun 12 15:47:29.343: ISDN Se0/0/0:23 Q931: RX <- PROGRESS pd = 8 callref = 0x8008

Progress Ind i = 0x8288 - In-band info or appropriate now available

Jun 12 15:47:30.795: ISDN Se0/0/0:23 Q931: RX <- CONNECT pd = 8 callref = 0x8008

Jun 12 15:47:30.831: ISDN Se0/0/0:23 Q931: TX -> CONNECT_ACK pd = 8 callref = 0x0008

Jun 12 15:47:36.099: ISDN Se0/0/0:23 Q931: TX -> DISCONNECT pd = 8 callref = 0x0008

Cause i = 0x8090 - Normal call clearing

Jun 12 15:47:36.343: ISDN Se0/0/0:23 Q931: RX <- RELEASE pd = 8 callref = 0x8008

Jun 12 15:47:36.423: ISDN Se0/0/0:23 Q931: TX -> RELEASE_COMP pd = 8 callref = 0x0008

I masked the area code but it is the correct one.


paolo bevilacqua Tue, 06/12/2007 - 15:35
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Hi Justin,

two things that possibly the telco wants to have different, perhaps they want the calling number to be your DID only, like 3 or 4 digits, let's say the same number of digits you receive for incoming calls. Then also check what plan/type they set for for incoming calls, so it can be set to be the same.


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