[Asterisk-Users] 911 Q

[Joel Newkirk]

Thank you - while not directly an answer to my question, it directly
addresses the root of my question, pointing me where I'll need to go to
dig deeper.  It also tells me what we didn't want to hear, that there's
a very good possibility that we simply won't be able to ensure that the
911 call center can tell which unit a call comes from without verbal
specification from the caller.

j

On Sun, 2005-10-02 at 08:13 -0600, Rich Adamson wrote:

> Asterisk is more then capable of sending the appropriate callerid info
> to any remote site including 911 centers. However, there is a telco between
> asterisk and the 911 center that may not have realistic policies/systems
> to accept and forward that callerid. So, your objective becomes one of
> what the telco will allow you to do (and their support of your objective).
> 
> As one example only, the telco might have a switch that does not have
> PRI capabilities (I know of many of these), but they provide ANI info
> to the 911 centers since that _might_ be the only data they can provide.
> If that were the case in your environment, it doesn't make any difference
> what you do with asterisk, it won't be supported.
> 
> I know from practical experience that a telco's switch (in most cases)
> will accept calleridnum via a PRI, but on most central office switches
> its an option that needs to be turned on. (Local telco policy _might_
> say they will never do that.) Once that option is turned on, you can
> send almost anything to them in the form of calleridnum.
> 
> The callerid name is a different story.  The central office switch that
> _terminates_ any call (including 911 calls) will have a mechanism to do
> a database lookup/dip, and if that database has not been populated with
> an appropriate callerid name, will not provide callerid names to the
> 911 center (or anyone else). That essentially says you can program
> asterisk to send anything that you want from a callerid name perspective
> and it will be ignored in the US. In very general terms, only telco 
> personnal have the access to update the callerid database, and usually
> that is limited to the CO prefixes they support.
> 
> Also keep in mind that not all 911 centers are the same from a technical
> perspective. They certainly accept callerid numbers, but they may have
> their own local database for names (etc), or, they may also do a database
> lookup from some distant database.  If you think about those customers
> that subscribe to callerid blocking, cell phones & gps, and the requirements 
> of 911 centers, its not hard to visualize several different 911 
> implementation approaches.
> 
> Talk to a knowledgable telco person (might be somewhat difficult to find
> the appropriate person), and talk to the 911 center manager to better
> understand what options you might have available. I'd start with the
> 911 manager as he will know a telco person that understands the
> technical requirements.
> 
> 
> _______________________________________________
> --Bandwidth and Colocation sponsored by Easynews.com --
> 
> Asterisk-Users mailing list
> Asterisk-Users at lists.digium.com
> http://lists.digium.com/mailman/listinfo/asterisk-users
> To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-users