# Line Interface Module Emergency Services Operation

## Description

The Line Interface module is an optional device that adds analog phone line (POTS) capability to a Mitel 5220 Dual Mode, 5224, 5324, 5330/5330e, 5340/5340e or 5360 IP phone. Emergency services pinpoint the origin of an emergency call by the CESID that is associated with the phone. This CESID is sent to a PSAP, which then directs emergency personnel to the source of the emergency. As an administrator, you must associate a single CESID with each phone. In a teleworker context, it is possible that a phone equipped with a Line Interface Module could be located in a different PSAP coverage area, than that of the enterprise, so its important that you ensure that the emergency services routing is correct (refer to Program Emergency Services for a Line Interface Module) to eliminate the possibility that an emergency call could be placed to the wrong PSAP.

CAUTION: A telephone with a Line Interface Module attached is not "mobile". The location of the Telephone Set is determined by provisioning and system configuration. Users are not allowed to change the location of the telephone set (except within the residence served by the analog line).

## Emergency call behavior in Teleworker Applications

The Teleworker phone will react in the following ways to emergency calls, depending on the configuration of the CESID Assignment form, and on the state of the analog phone line (free, busy, or disconnected). See the table below for the expected behavior from various scenarios.

User Action | Line Interface Module Line State | Emergency Call Routing Option
Analog Line First | Analog Line Only
Pick up handset, select Analog line, and dial 911. | Line Interface Module line is available. | Dial tone is provided by the PSTN and the local PSTN handles the emergency call. Not available if the Line Interface Module is configured for Failover Only mode.
Line Interface Module line is in use or unplugged. | No dial tone is provided. Not available if the Line Interface Module is configured for Failover Only mode.
The telephone set is not registered, and the line is available. | The telephone set is in Failover Mode (the analog line is selected automatically). Dial tone is provided by the PSTN and the local PSTN handles the emergency call.
The telephone set is not registered, and the line is unplugged. | The telephone set is in Failover Mode (the analog line is selected automatically). Dial tone is not provided.
Pick up handset and dial 911. | Line Interface Module line is not in use. | Line Interface Module dials 911 to local PSTN. | Line Interface Module dials 911 to local PSTN.
Line Interface Module line is in use. | Line Interface Module is NOT used. System emergency call routing proceeds to system PSAP. | Busy indication is provided, and the display shows "Lift handset, select analog line." Privacy is released for a specific period of time.
Line Interface Module line is unplugged. | Line Interface Module is not used. System emergency call routing proceeds to system PSAP. | Busy indication is provided, and the display shows "Lift handset, select analog line." Privacy is released for a specific period of time.
Dial 911 handsfree. | Line Interface Module line is not in use. | Line Interface Module is NOT used. System emergency call routing proceeds to system PSAP. | Busy indication is provided, and the display shows "Lift handset, select analog line." Privacy is released for a specific period of time.
Line Interface Module line is in use. | Line Interface Module is NOT used. System emergency call routing proceeds to system PSAP. | Busy indication is provided, and the display shows "Lift handset, select analog line." Privacy is released for a specific period of time.
Line Interface Module line is unplugged. | Line Interface Module is NOT used. System emergency call routing proceeds to system PSAP. | Busy indication is provided, and the display shows "Lift handset, select analog line." Privacy is released for a specific period of time.

NOTE: Cases in bold should not be configured if the call might be placed to a PSAP that is not in the same region as the user.

Related Topics

- Program Emergency Services for a Line Interface Module