Chapter 1      Overview of ALI Formatting Tool

Overview of Enhanced 911

Overview of Enhanced 911

Cisco Emergency Responder (CER) helps you manage emergency calls in your 

telephony network so that you can respond to these calls effectively and so that 

you can comply with your local ordinances concerning the handling of emergency 

calls. In North America, these local ordinances are called  enhanced 911,  or 

E911. Other countries and locales might have similar ordinances.

Enhanced 911

 (E911) extends the basic 911 emergency call standard to make it 

more reliable.

In basic 911 in North America, if a caller dials 911, the call is routed to a 

public 

safety answering point

 (PSAP), also called the 911 operator. The PSAP is 

responsible for talking to the caller and arranging the appropriate emergency 

response, such as sending police, fire, or ambulance teams.

E911 extends this standard with these requirements:

The emergency call must be routed to the local PSAP based on the location 

of the caller. In basic 911, the call simply needs to be routed to some PSAP, 

not necessarily the local one.

The caller's location information must be displayed at the emergency 

operator's terminal. This information is obtained by querying an 

automatic 

location information

 (ALI) database.

In E911, the location of the caller is determined by the 

emergency location 

identification number

 (ELIN), which is a phone number the PSAP can dial to 

reconnect to the emergency caller if the emergency call is cut off for any reason, 

or if the PSAP simply needs to talk to the caller again. The emergency call is 

routed to the PSAP based on the location information associated with this number. 

For multi line phone systems, such as an office system, the ELIN can be 

associated with more than one telephone by grouping the phones in an 

emergency 

response location

 (ERL). In this case, the location the PSAP receives would be 

the address of an office building. For large buildings, the location would include 

additional information such as floor or region on a floor. Each ERL requires a 

unique ELIN.

Related Topics

Overview of the ALI Formatting Tool, page 1 3

Understanding E911 and Cisco Emergency Responder Terminology, 

page 1 4

ALI Formatting Tool User Guide for SBC Pacific Bell

1 2

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