VoIP and E911

[TimAbney]

We are just starting to roll VoIP to remote locations and we're coming up with some E911 questions. We are sending IP phones home with a select group and are trying to spoof their home numbers for 911 calls. We can see the CLID and the calling # composition appears to be working ok but the call is not routed to the proper PSAP. We are checking with the carrier of our CAMA trunks to see if they are blocking the CLID. I'm looking for input from other people about how you are handling this situation. Thanks for the input.

 

[johnpoole]

if the clid spoof works.. ie your sending the home clid, then look to your carrier. your playing by the rules, he needs to play well with others..

carriers need to get this cleaned up, it's growing faster then they are learning

john poole
bellsouth business
columbia,sc

 

[TimAbney]

We got a message back from our provider saying that our problem is because all providers don't input information into a common database. I thought there was a DB that is kept up for all of the western US. Can anyone out there shead some light? I can't believe there isn't a fix for this issue.

 

[dgrizzard]

The naming of the CLID would be the only change between carriers and areas. The number should remain the same as that is what is being sent across the trunks. For instance if I call from my Verizon phone to an ATT (or a Brighthouse residential customer) they may have a different (or none) name for my number. But the number should still be the same. It would not go to the right PSAP though if they do not have the NPA-NXX programmed correctly.

Example:
Main office is 407 area code, call originates from 813 area code (with the 813 CLID), and the provider sends the call to the 407 PSAP since that is where they think the call originated from (main office).

Verizon has a solution for this using their SIP trunking, they create locations for you and then I just send the CLID for that location. They send it to the correct PSAP with the address, etc.

A solution for this (if your provider is the problem) is to send your 911 calls out a local trunk at that office. If you do not have any CPE out there you could always get an Audiocodes FXO and just put a B1 line out there.

 

[TimAbney]

nike thanks for the input but you're not quite on track here.

We are using IP phones at employees' homes. They register back to our PBX. If they use the IP phone to make a 911 call and we use the same CLID as their desk phone the PSAP recieves information as though they were calling from thier office.

We want to send their home number so the correct PSAP gets the call with the correct address. IfIn our tests the call goes though to the wrong PSAP and there is no number or address information delivered to the PSAP agent

 

[gwebster]

There are a number of excellent videos on youtube. Do a search for "nortel e911".

 

[BombOne]

I have a site doing this, but I subscribe to e911 service. I dont send there home number, just a unique number for each person, then the e911 data base takes care of it from there. Im sure you could make it work with home numbers, but not with e911 service. Is that what you are trying to avoid, buying the service?

 

[dgrizzard]

I didn't realize that you were trying to spoof a CLID that wasn't on your service provider to begin with. But the principle is pretty much the same as what I was talking about, but in this case you are trying to send a CLID that is not part of your (let's call it a calling domain) service with the provider.

This may be something your service provider has implemented to prevent people from CLID spoofing. In other words if you don't own the number than you can't CLID based on that number. I know that is true for the SIP trunking I'm currently getting from VZ. If I send a (invalid) CLID that isn't on one of my locations I can't even dial out the trunks.

What you're wanting to do is send out any CLID you want (regardless of if you "own" it) and have it recognized and sent to the PSAP. Depending on your provider they may have something that will allow you to do this (or maybe not).

 

[TimAbney]

Nike I was originally leaning toward the provider is blocking line of thinking but the response I got from them was the other provider isn't playing right. Always with the finger pointing.

 

[TimAbney]

Bombone We have PS ALI that we administer for our number plan. We can send the "Spoofed" number for a regular call with no problem across our trunks from the same provider that we get our CAMA trunks from. I'll have to dig deeper on their side for an answer.

 

[Avaya911PLM]

Tim-

Is the user in the SAME selective router as the main PBX? Remember, Selective Routers do not talk to each other.



--
Fletch

Nortel Emergency Services PLM

http://nortel.com/e911

Check out this month's E911 Talk podcast at Nortel E911 Talk Podcast

 

[TimAbney]

Appearantly some of the providers in our area do not update the Intrado DB and I'm being told that is the problem. Our CAMA trunk provider uses the Intrado DB for look ups and the other providers use a local DB. Since the two DBs don't interact our spoofed CLIDs come up empty for these spoofed calls.

 

[Avaya911PLM]

Wow, that is a problem! Local DB's do provide a quick fix, but then again your run into situations like you have, and that is no good for anyone!


--
Fletch

Nortel Emergency Services PLM

http://nortel.com/e911

Check out this month's E911 Talk podcast at Nortel E911 Talk Podcast