Multi Line Telephone System (MLTS) Best Practices

The CRTC Interconnection Steering Committee – Emergency Services Working Group (ESWG) has undertaken extensive research regarding the applicable laws and practices in Canada and the United States. Since Canada does not have similar legislation, this document provides very important MLTS configuration practices for Canadian MLTS owners, operators, providers, and/or resellers. These best practices ensure 9-1-1 calls are received locally with accurate location information. The following list of stakeholder specific best practices will be updated as required.

1. For Telecommunications Service Providers (TSPs)

1. The ESWG recognizes that some 9-1-1 network providers offer Private Switch-Automatic Location Information (PS-ALI) or equivalent service (including equivalent Next Generation 9-1-1 (NG9-1-1) service solutions) to manage Customer Name and Address Information (CNAI) and encourages those entities that do, to continue to do so.
2. TSPs and applicable resellers provide services allowing MLTS providers, resellers, owners, and operators to access local 9-1-1 systems in alignment with all MLTS best practices.

2. For MLTS Owners, Operators, Providers, and/or Resellers

Accessing 9-1-1 Services

1. Direct dialing (without requiring any prefix or code) to 9-1-1 from any MLTS be implemented as part of the provisioning of the service, where technically feasible.
2. In cases where the MLTS dial plan uses dialing prefix(es) for regular calls (e.g., local, domestic long distance, and international long distance), the dial plan should be set up to reach 9-1-1 with or without existing dialing prefix.
3. MLTS calls should be routed directly to the public safety answering point (PSAP) without being directed to a central internal answering position such as a security desk, receptionist, or operator.

Caller Location Information and 9-1-1 Call Routing

1. MLTS owners, operators, providers, and/or resellers work with their TSP to assign a unique Automatic Number Identification (ANI) Automatic Location Indicator (ALI) for identifying the location of each fixed endpoint or group of co-located devices used to contact 9-1-1. This could be accomplished through an automated or manual process leveraging the existing incumbent local exchange carrier (ILEC) ANI/ALI procedures (or NG9-1-1 equivalent).
2. MLTS owners, operators, providers, and/or resellers work with their TSP to ensure sufficient location details are made available to the 9-1-1 system and PSAP to assist in quickly ascertaining an accurate location and enable direct routing of 9-1-1 calls from fixed endpoints.
3. MLTS owners, operators, providers, and/or resellers should configure systems where possible to:
   1. provide an ANI assigned to an accurate location when the location of the caller is known, or
   2. provide the default location associated to the local MLTS, or
   3. default to the nomadic Voice Over IP (VoIP) 9-1-1 call processing if the location is not fixed or cannot be determined.
4. The phone number provided to the PSAP should be dialable from outside the MLTS, allowing the PSAP to call the endpoint back if necessary.
5. Tools or methodologies be implemented to ensure appropriate management as they relate to 9-1-1 for:
   1. The accurate ANI and location data at the time of the 9-1-1 call to facilitate local call routing and providing location data to the appropriate PSAP.
   2. Where possible, mitigate the known issues related to nomadic endpoints and users.
   3. Where possible, mitigate the known issues related to a centralized MLTS servicing multiple physical buildings and/or locations.

Awareness and Notification

1. Notifications should be issued to on-site or off-site personnel with the relevant information (including who, when, and where) that someone connected to the MLTS dialed 9-1-1. Notification should occur in parallel and without interrupting or altering the call path to 9-1-1.
2. Notifications should be issued to on-site personnel trained in providing direction to first responders to quickly get to the site of the emergency.

MLTS Implementation

1. MLTS owners, operators, providers, and/or resellers should include end-user educational materials explaining:
   1. The risks and benefits of provisioning accurate location information for use when 9-1-1 is dialled. If end users are made aware of the risks they can ask appropriate questions and make informed decisions on deployment.
   2. Any risks with requirements for prefix dialing. If end users are made aware of the risks they can ask appropriate questions and make informed decisions on deployment.
2. MLTS owners, operators, providers, and/or resellers should accurately program and test MLTS to deliver and display information required at the appropriate PSAP including ANI and dispatchable location.
3. MLTS owners, operators, providers, and/or resellers should install and maintain systems with the same level of 9-1-1 service that other users connected directly to the PSTN receive. The following information should be included with the 9-1-1 call:
   1. Appropriate callback number to reach the calling party such as a direct inward dial (DID) number, internal extension or front desk in the event a DID number or internal extension is not accessible.
   2. Specific accurate location of the 9-1-1 caller.
   3. Additional information about the caller’s location (such as: building name or number, floor, section or room number) to better direct responders to the caller’s specific location.

Plan for the Future

1. ESWG recommends that MLTS owners, operators, providers, and/or resellers begin planning for NG9-1-1 by discussing plans with their MLTS vendors to make “additional data” available to PSAPs. These discussions should take into consideration that the framework and timelines for additional data (provision, transmission, and access) in Canada are currently in the planning stages.

ESWG submits that these recommendations and best practices be implemented as soon as practical and appropriate by all parties.

Date modified:

2022-11-21