PS/ALI on option 61c for E-911

[deelee74]

I have asked this before, and noone answered. I thought I would try again.
I have a college campus that has purchased PS/ALI software for E-911 (which is now the law in Illinois).

The software tells the 911 dispatcher where the calling party is located on campus by identifying the caller by their extension number instead of just the trunk they are dialing from.
They have keyed in their campus-wide database into the PS/ALI program, and they are ready to upload the database to Temple Terrace, FL. Temple Terrace will then update our local HP-3000 with the building number and room number of each DN on campus.

How on earth do we get the Option 61 to send out the information about which DN is calling 911?!!

The customer has PRI for all of its outgoing trunks. When this PRI was installed, the customer was told that it would give them the capability of identifying individual DN's calling 911 without having to do anything other than simple programming on the switch.

Our sales team is now telling the customer that they will have to purchase a block of 2000 DID numbers. Then each phone will be given a DID number for identification purposes only. The PBX will send out the DID digits which will show up on the 911 terminal as "Building x, Room x on campus".

I don't believe that this is true. I was told that the d-channel of the PRI can be somehow used to send identifying digits for specific calling parties.

If the customer had to buy 2000 DID's, it would require a whole new NXX to be added to the CO. This is a rural community college.

The cutoff date for getting this done is quickly approaching.

Can anyone help?

thanks

 

[Slackliner]

We have 'zones' set up where a DID represents a certain area (building, wing, floor, etc.). Then we define that DID in our CLID table. For internal extensions, we determine which zone the set is closest to, then associate that zone's CLID to the primary DN. (and all other DN appearances refer to the CLID entry on key 0).

There is a problem with this... if someone calls an outside number - and then the called party wants to return the call based on the CLID, they will wind up calling the phoneset that has the true DID appearance.

So, we end up having to define some DID's with vague geographical CPND assignments (ex. S Pav Flr 4 Lobby). Ultimately, as long as we get the aid car to the general vicinity, the people in that area can take over getting the medic to the precise location.

 

[deelee74]

the customer wants to do this without using DID's.
They were told that they could utilize their PRI somehow.

 

[jgideon]

Not without the numbers being DID's. In Illinois, the two ways of getting station information to a PSAP are through PRI, or through CAMA trunks. PRI is actually cheaper, but both implementations assume that the 'displayed' number is a DID number. The 'link' that indexes location is a phone number, period. The PRI will transmit Calling Party Number, but I don't believe there is a way to 'fake' the number on the PSAP side to be a non-DID number. All of the implemenations I've worked with (15+ since 1988) in Illinois converted to DID's.

I believe that the regulation will allow you to use a 'grouped' DID for phones that are in the same 'location', but from a 'life safety' standpoint, I'd go with the DID's...

 

[4wem]

The Sales guys will tell you that it is not a problem making the PBX send the DN on the PRI's d-channel...and that is true enough. But the problem is that nobody at the PSAP will know what the heck they mean when they recv it. Which is why the DID's are necesary. The DID's are identifiable beyond the name of the campus, or company, or the whatever entity is buying them.

Purchasing DID's that mimick your DN's in the dialplan is the secret to making it easy to manage. Assign a DN to a user that uses a DID with the same extension.