911 PSAP not receiving ANI

Unanswered Question
Dec 21st, 2007

I have deployed Callmanger 5.1 with CER 2.0, and I am sending out a 10 digit Calling Party Number set up in the CER ERL. The calls go to the PSTN through 2 PRIs setup as a MGCP gateway. PRIs setup as NI2. I have verified the Calling Party Number sent when dialing 911 thru debug q931 on the router.

Calls get answered by the PSAP, but no number (and location) is displayed at the PSAP. The ANI is seen on the Telco's PRI Switch, but is not being sent to the PSAP for ALI lookup.

Is there any configuration setting on the Callmanager MGCP gateway setup that needs to be disabled/enabled for the Telco to forward the Calling Party Number as E911 ANI?

I have this problem too.
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Paolo Bevilacqua Fri, 12/21/2007 - 11:15


If the q931 trace shows that you are passing the calling number OK, there is nothing else you can do, and the problem is in the telco network and what else is connected there.

Beside, even if you were to block the calling number, or sending a different one, calls to 911 must still be able to show who is calling to the operator, based on the the physical circuit on which the call is received.

This is the way it works universally, and if it doesn't in your case, be reassured it's not your fault.

Hope this helps, please rate post if it does!

mciarfello Sun, 12/23/2007 - 22:33

Hi Robby,

As p.bevilacqua said, you have to call your telco provider and have them pass the ANI through to the 911 PSAP.

This is usually a different path through THE PROVIDER'S switch than normal calls. As a test, you can change your CER 911 pattern and your CallManager route pattern to, say, call your cell phone instead of 911 to test. You may get the ELIN properly displayed on your cell phone. But still get nothing received by the PSAP. Don't forget to change the ERL of your test phone so you get the right pattern to your cell phone.

The provider may make you sign a form releasing them of any configuration errors because they just tie the physical circuit to your address. A config error on your part may send the responders to the wrong address.

Any ANI you send is probably being overwritten with your billing telephone number (or similar number) when making a 911 call. Funny why it came up with nothing.

The CLEC of one of my customers never did that type of configuration before (listening to the customer ANI, so had to do some research themselves and we had to conduct many tests. So you may want to schedule testing with the PSAP ahead of time so you don't piss them off.

I was fortunate with my testing, I was testing from within the PSAP for this customer. lol.

ROBBY HARRELL Mon, 12/24/2007 - 05:36

I work for the local Telco installing and configuring customer CPE. I worked with our Translations group Friday on these PRIs. Currently, a default 911 number is assigned to these PRIs. That is what is seen by the 911 center. When we remove the default, the PSAP get an ANI failure, no caller-id is shown. Our 911 group is going to look at the 911 Tandem Router later to see if they see the Calling Party Number info we are sending out the PRIs. We verified the ALI info on some of the DIDs the CER is using by using them as the Default 911 number for the PRIs.

mciarfello Tue, 12/25/2007 - 21:55

From what I gathered from my provider when I went through this, there was special configuration in the switch (or switches) when a 911 call is routed. So it looks like you are seeing similar symptoms when you remove the defaults. The PSAP kept receiving "NO ANI RECORD FOUND" when we made test calls.

I think they even had to open a ticket with the PBX manufacturer (forgot what it was) for configuration assistance.

Wish I could help you out more. Keep us informed. This could help future net-pro'ers.


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