Utilizing sip messages to determine the status of a remote terminal in VOIP communication systems

Abstract

There is a growing problem in correctional facility telecommunications systems in which parties on a voice call may connect inmate callers with restricted parties. Prison communication systems monitor calls to prevent such activity, but in Voice over Internet Protocol (VoIP) environments such systems may fail to detect this activity. The present disclosure provides details of a system and method for using SIP messages common in VoIP environments to detect illicit activity initiated by a party on a voice call within a controlled environment. Scenarios are detected in which a called party connects an inmate caller to a restricted party via three-way call conferencing, call forwarding, or other call features. Corrective actions are then taken when such activity is detected, such as call blocking or alerting officials illicit activity is occurring.

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