Outbound CID on T1 E&M

Unanswered Question

Turning up some new LD outbound only T-1's. A call that uses these T-1's is not sending CID information. We have the external number mask setup on the DN, which worked fine before with the PRI. I have seen some comments regarding caller-id with certain types of E&M.

The provider said we need to use E&M wink-start signaling.

What changes will need to be made to get outbound CID working? Another signaling type from the provider?

Here is the config on the controller.

controller T1 0/2/0

framing esf

linecode ami

ds0-group 0 timeslots 1-24 type e&m-wink-start

This is running with CM5.1 and MGCP gateway type.

I have this problem too.
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Paolo Bevilacqua Wed, 02/06/2008 - 09:58


there is no established standard for caller-id on E&M, inbound or outbound. Ask your SP if they perhaps expect called and calling number to be separated, by a * perhaps. In that case, something may be done.

The easy alternative is using PRI and with that everything works per standard.

Hope this helps, please rate post if it does!

Paolo Bevilacqua Wed, 02/06/2008 - 11:30

Hi, since you are using mgcp, debug voip dialpeer will not show anything.

You can see the low-level on the interface with "debug vpm signal".

I actually get information from debug voip dialpeer but the called # and calling # are blank.

debug vpm signal doesnt show me any CID information. I want to see if the gateway is even seeing the CID information and not passing it out the T-1. I dont think Callmanager is even sending to the gateway.

How do I know that CID is even getting there?

pcameron Wed, 02/06/2008 - 16:55

The short answer is that with North American service providers, unlike ISDN PRI there is no standardised way of passing caller ID (ANI) on T1 CAS.

By default, if you use E&M wink or immediate start operation, there is no support for ANI for either inwards or outwards calls.

Technically you could use a TCL script to manipulate the digit strings, but this would have to be a custom script and it's developement or operation is beyond the scope of this forum. You could also be assured such a script would require further customisation if used with different service providers.

Refer to the attached document for more background.


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