| 摘要 |
A blacklist of known harassing or non-legitimate emergency calls is maintained. An incoming emergency call is checked against emergency call records to determine if multiple emergency calls have been made recently, from the same general location, and destined to the same PSAP. Feedback is provided regarding the number of recent calls made and the possibility of a false positive, based on call history from known handsets in the area, including the possibility of a phone with a known MEID/ESN, when powered up, receiving the same 911-xxx-xxxx. Blacklisting may be approved or not based on the feedback. A telephone number or MIN may be placed on a "blacklist" with a 'timer'. Subsequent calls to that phone number will be assigned a different SIP URI (a unique URI per destination determined prior to lookup on the blacklist) and be directed elsewhere. The call may be completed to an administrative line. |
