APPLICATIONS

Basic Configuration   (Single Tandem)

Overview

The Dial-Up Network Control Modem (Dial-Up NCM) was designed to allow PSAP supervisors to remotely signal the 9-1-1 tandem switch to re-direct 9-1-1 calls to an alternate PSAP.

The Dial-Up NCM allows one or more supervisors, regardless of their location -- whether in the building, the parking-lot, across town, or even in transit -- to switch voice traffic to an alternate answer PSAP, in a secure, quick, and easy manner, using only a standard touch-tone phone. This useful capability helps to speed resumption of 9-1-1 service in the event of a local system failure, but is especially important for situations where access to the PSAP building itself has become unsafe or impossible, such as in a fire, during a flood, or after an earthquake.

Operation

An ordinary landline or mobile touch-tone phone is the only additional equipment needed to operate the Dial-Up NCM, as standard DTMF touch-tone is used for entering all passwords and commands, and a synthesized human voice provides all prompts, responses, and status information.

As the Dial-Up NCM uses a standard dial-in phone connection, it can be conveniently accessed from anywhere, using any available touch-tone phone. This great flexibility does not come at the expense of good security however. To prevent unauthorized access, the first prompt accepts only pre-specified call-back phone numbers, or a special immediate-access bypass-password, and separate passwords are required thereafter, to actually access relay-control or setup-mode. In addition, these electronic security measures can be combined with the usual physical measures to provide many management options. As different ranks of supervisor need different levels of transfer-key access -- by pre-approved office phone, pre-approved mobile phone, or any phone they can grab the fastest -- the callback numbers and bypass-password provide a manager-selectable balance between security and flexibility.

Each Dial-Up NCM supports one or more relays and each individual relay may be switched on or off as needed. A standard short script of verbal prompts guides the user through the procedure of logging in, correctly setting, and verifying each relay. As this script has been carefully tailored in response to customer feedback, it should be suitable for most applications, but additional scripts and commands can be provided by special order. Contact Informer for details and prices regarding customization options.

Installation

The Dial-Up NCM would normally be installed at the Tandem Central Office and be connected to both a standard loop-start trunk line, and the tandem switch itself. On the switch, the Dial-Up NCM is connected to the scan points that control the transfer of voice traffic. When the Dial-Up NCM receives a transfer-command from a supervisor, it closes its relays as specified, causing the corresponding scan points to saturate. This activates the remote make busy feature on those lines and the associated 9-1-1 calls are re-routed to an alternate PSAP. No additional equipment is required, and any stationary transfer keys continue to work in parallel.

Informer's Dial-Up NCM provides a secure, convenient, useful, and potentially imperative capability for the prepared PSAP supervisor.

Dial-Up NCM & NCM Alarm Unit

The Dial-Up NCM can be added to the standard NCM Alarm Unit setup to provide both robust, instant-access control from PSAP itself, and convenient, flexible, remote control from external locations. In this configuration, the Dial-Up NCM again resides at the Tandem Central Office, still connected to the tandem switch scan points but now in parallel with a standard NCM Card. The NCM Alarm Unit resides at the PSAP, serving as the hand-switched transfer-key. As the NCM Alarm Unit is hard-wired to the standard NCM at the tandem (via the PSAP alternate answer circuit), there is always a durable physical control path directly to the tandem switch -- or an audible and visual alarm should that path fail. As the Dial-Up NCM is connected to the general phone system, there is always a convenient and flexible alternative control method available.