Some time ago I attended a Cisco Call Manager demo, and was told that the E-911 could identify the location in the building by floors if each floor used a different subnet. The implication was that the subnet was the basis of identifying the floor the phone was on.
Is that still possible? What programming is necessary to make it work?
Phil
PacketBrain - Training and Consulting
Train Your Brain
|
Mon, 11/09/2009 - 2:04pm
|
"Cisco Emergency Responder achieves this breakthrough in E9-1-1 administration by transcending the traditional method of associating a user's phone number to a physical location.
Rather than sending the caller's phone number in the calling party number field of outbound emergency calls, Cisco Emergency Responder sends a different Direct Inward Dial (DID) number that represents the current physical location of the caller.
This substitute DID number, called an Emergency Location ID Number (ELIN), acts as a key to the location database which local exchange carriers and PSAPs use to route calls and identify caller location. Data from physical floor plans and site cabling plans are posted a single time to a Private Switch Automatic Location Identification (PS-ALI) database, and no additional updates are required for any user moves, adds, or changes."
from: http://www.cisco.com/en/US/prod/collateral/voicesw/ps6789/ps7046/ps842/p...
The very quick explanation is that through CER, you map physical switch ports to these substitute DID numbers, called ELINs. CER then looks up phone MAC addresses in the CUCM database and then consults the switch MAC tables to build a mapping table of phones<-->switch ports.
After that has occurred CER, now knows which phone numbers should map to which ELINs, so that when a 911 call is placed from any phone on the campus, the proper ELIN is inserted on the fly.
The ELIN to physical building location map is provided by the company to the PSAP to populate the ALI database.