General Overview of 911 calling from MTLS phones
1. Understanding Enterprise 911 (from Plante Moran)
2. Enterprise E911, A Primer (a PDF from Plante Moran)
Both Plante Moran documents are excellent, particularly the Primer that has an excellent non-technical overview, a discussion of many key issues including ERLs, a great review of each switch vendor’s E911 capabilities, a description of PS/ALI, a list of special vendor offerings, etc. Required reading for any organization considering MLTS/PBX E911 implementation.
3. Private Switch 911 Overview (from Tarrent County TX 911, 2009)
4. Cambridge MA (City) Comments on PBX-E911 and Use of PS/ALI. (City of Cambridge)
This document explains the steps Cambridge went through to implement their E911 MLTS solution on their Nortel CS1000 switch (Fall 2009) using the simplfying ERL concept.
B. Overview of Massachusetts MLTS E911 Statute Law and Regulations:It is estimated that over one million wired phones in Massachusetts cannot transmit their exact location information to PSAPs when a 911 call is made from “PBX-connected” phones. These are phones connected to “Multiline Telephone Systems” ((MLTS) – also called Private Branch Exchange telephone systems (or PBXs). PBX’s are found mostly in businesses, hotels, universities, government offices and other facilities. Often you know you are using a “PBX phone” when you have to dial a “9” or “8” to get an “outside line”. Another way you might know you are using a PBX phone is if someone has told you you are using a VoIP or “IP” phone in your business, school, hotel, or other larger organization.
Massachusetts’ new E911 statute contains language that requires “new or substantially renovated multiline telephone systems” installed after 7/1/09 to “provide the same level of enhanced 911 service that is provided to others in the commonwealth”. Regulations will be developed to implement this statutory requirement. See the complete language below:
“Section 18J. Beginning July 1, 2009, any new or substantially renovated multi-line telephone system shall provide the same level of enhanced 911 service that is provided to others in the commonwealth. The department shall adopt regulations to implement this requirement. In such regulations the department may exempt certain multi-line telephone systems from this requirement based on such factors as costs and the public benefits of compliance, except that accessibility of such a system to people with disabilities may only be waived if the proponent of the waiver has shown it to be technologically infeasible or of excessive cost without benefit to the disability community. For the purposes of this section, a “multi-line telephone system” shall mean a system comprised of common control units, telephones and control hardware and software providing local telephone service to multiple end-use customers in businesses, apartments, townhouses, condominiums, schools, dormitories, hotels, motels, resorts, extended care facilities, or similar entities, facilities or structures. “Multi-line telephone system” shall include: (1) network and premises based systems such as centrex, pbx and hybrid key telephone systems; and (2) systems owned or leased by governmental agencies, nonprofit entities and for-profit businesses.
Mass. promulgated MLTS E911 regulations effective 7/1/09. They should be required reading for any entity installing a new PBX – or substantially renovating one – on or after 7/1/09.