When someone dials an emergency number from an Avaya IP telephone, the emergency call reaches the local emergency service in the PSAP only when the telephone system has local trunks. If someone dials an emergency number from a remote location that does not have local trunks, an Avaya IP telephone cannot dial to and connect with local emergency services. To avoid possible delays in getting emergency aid, do not use an Avaya IP telephone to dial emergency numbers from a remote location. Avaya is not responsible or liable for any damages that might result from misplaced emergency calls that someone makes from an Avaya IP telephone. Your use of Communication Manager indicates that you have read this advisory. You further agree to use an alternative telephone to dial all emergency calls from remote locations. If you have questions about emergency calls from an IP telephone, go to the Avaya Support website at http://support.avaya.com for related documentation and knowledge articles .
When someone dials an emergency number from a wired IP telephone, the system assigns an Emergency Location Information Number (ELIN) through an IP subnetwork. The system then sends the ELIN over either CAMA or ISDN PRI trunks to the emergency services network. To use this capability, you must have subnetworks that correspond to geographical areas.
The E911 for wired IP telephones capability works with two types of IP protocols:
H.323
SIP
If someone dials an emergency number from a wired IP telephone, the system at the PSAP uses the CPN to look up the physical location of the caller. However, the CPN might not always correspond to the physical location of the caller, because users with:
H.323 IP telephones can move the telephones without notifying the system administrator
SIP IP telephones can use the same extension simultaneously at several different telephones
Without the E911 for wired IP telephones capability, the emergency response personnel might go to the wrong physical location. With the E911 for wired IP telephones capability, the system properly identifies the location of the caller. The emergency response personnel can go to the correct physical location, even if an emergency call comes from a bridged call appearance.
When someone uses an IP telephone to dial an emergency number, the software compares the following two values for that IP telephone:
The Emergency Location Extension field on the IP Address Mapping screen
The Emergency Location Ext field on the Station screen
If the two values are the same, the telephone most likely did not move. If the telephone did move, the telephone moved within the same subnetwork. In this scenario, Communication Manager sends the station’s own extension as the Calling Party Number (CPN) .
If the two values are different, and if the Emergency Location Extension on the IP Address Mapping screen is not blank, the telephone moved from one subnetwork to another. In this scenario, Communication Manager sends the CPN that is on the IP Address Mapping screen.
If the Emergency Location Extension on the IP Address Mapping screen is blank, the administrator expects the caller to be located outside the LAN. This situation is true for a softphone. In this scenario, the CPN sent by Communication Manager is the Emergency Location Extension on the Station screen.
Whenever you add an extension as an Emergency Location Extension to the IP Address Mapping screen, check all Station screens for telephones in that IP address range.
If the telephone is a DID number, ensure that the Emergency Location Extension is the same on both the Station screen and the IP Address Mapping screen.
If the telephone is not a DID number, ensure that the Emergency Location Extension on the Station screen is different from the Emergency Location Extension on the IP Address Mapping screen.
