Detecting, verifying, and preventing unauthorized use of a voice over internet protocol service

A computer system for detecting, verifying, and preventing unauthorized use of a Voice over Internet Protocol (VoIP) service, the computer system comprising one or more processors, one or more computer readable tangible storage devices, and program instructions stored on at least one of the one or more computer readable tangible storage devices for execution by at least one of the one or more processors, the program instructions executable to:

• in response to receiving a VoIP call from a caller, check whether a record of a caller number of the VoIP call exists in a database including information of unauthorized uses;
• in response to determining that no record of the caller number exists in the database including the information of unauthorized uses, rate the VoIP call, based on a database including information of the caller number;
• set a predetermined time period for the VoIP call, based on a rating of the VoIP call;
• add the predetermined time period to a session initiation protocol (SIP) invite;
• connect the VoIP call to a called party;
• in response to that the predetermined time period is reached, interrupt the VoIP call and prompt the caller to conduct user verification;
• and
• in response to that the caller is successfully verified, reconnect the VoIP call to the called party.

A computer-implemented method for detecting and preventing unauthorized use of a Voice over Internet Protocol (VoIP) service, the method comprising:

• in response to receiving a VoIP call from a caller, checking a caller number of active calls in a database about live calls;
• determining whether another call is in progress from the caller number;
• in response to determining that another call is in progress from the caller number, determining whether the VoIP call is originated from an Internet Protocol private branch exchange (IP PBX);
• in response to determining that the VoIP call is originated from the IP PBX, determining whether the VoIP call is within an allowable number of calls from the IP PBX;
• and
• in response to determining that the VoIP call is not originated from the IP PBX or in response to determining that the VoIP call is not within the allowable number of calls from the IP PBX, blocking the VoIP call.