E911 Glossary of Terms

Enhanced 911 or E911 service is a North American telephone network (NANP) feature of the 911 emergency-calling system that automatically associates a physical address with the calling party's telephone number as required by the Wireless Communications and Public Safety Act of 1999. This is generally done by a form of reverse telephone directory that is supplied by the telephone company as a computer file, used to associate the caller's phone number with a physical street address. It provides emergency responders with the location of the emergency without the person calling for help having to provide it. This is often useful in times of fires, break-ins, kidnapping, and other events where communicating one's location is difficult or impossible.

Here is a list of common acronyms used in the E911 market:

• ALI: Automatic Location Identification
• ANI: Automatic Number Identification
• CAMA: Centralized Automatic Message Accounting
• DID: Direct Inward Dialing Number
• DTMF: Dual Tone Multi-Frequency Tones
• ISDN: Integrated Services Digital Network
• LAN: Local Area Network
• MF Tones: Multi-Frequency Tones
• ELIN: Emergency Location Identification Number
• ERL: Emergency Response Location
• MSAG: Master Street Address Guide
• NENA: National Emergency Number Association
• PBX: Private Branch Exchange
• PRI: Primary Rate Interface
• PS/ALI: Private Switch ALI
• PSAP: Public Safety Answering Point
• Tandem CO: Tandem Central Office or E911 Control Office
• TAPI: Telephone Application Programming Interface

• Enhanced 911
• E911 FAQ
• Glossary of Terms
• E911 Legislation