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

Patent metadata

Field	Value
Publication number	US-9614974-B1
Application number	US-201615360847-A
Country	US
Kind code	B1
Filing date	Nov 23, 2016
Priority date	Nov 23, 2016
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

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.

First claim

What is claimed is:

1. A method for detecting fraudulent activity in a communication system in a correctional facility, comprising:
receiving a packet stream associated with a voice call between an inmate calling party and a called party, the packet stream served through Voice over Internet Protocol (VoIP) within the correctional facility;
determining a call phase of the voice call, wherein the call phase is one of a call setup phase and a call established phase, the call established phase occurring after a successful end of the call setup phase;
flagging, during the determined call setup phase, a first session initiation protocol (SIP) message within the packet stream as suspicious based at least in part on a first message type of the first SIP message, the first message type indicating a first new party distinct from the called party and the inmate calling party, wherein the first message type is one of a 181 Response or a 3xx Response, wherein 3xx in the 3xx Response represents an integer between 300 and 399;
flagging, during the determined call established phase, a second SIP message within the packet stream as suspicious based at least in part on a second message type of the second SIP message, the second message type indicating a second new party distinct from the called party and the inmate calling party, wherein the second message type is one of an INVITE or a REFER;
confirming that a fraudulent activity has occurred based at least in part on at least one of a first content of the first SIP message, a second content of the second SIP message, or a third content of a third SIP message received after the first SIP message or the second SIP message, wherein the first content, the second content, or the third content confirm that the first new party or the second new party is not allowable for the inmate calling party;
sending a confirmed infraction log to an administrative workstation based on the confirming, wherein the confirmed infraction log comprises a confirmed infraction type; and
triggering a corrective operation in response to the confirming.

2. The method of claim 1 , further comprising detecting a real time protocol (RTP) packet stream between the inmate calling party and the called party, wherein the detecting indicates the successful end of the call setup phase.

3. The method of claim 1 , wherein the first message type is the 181 Response, and the method further comprises sending a suspected infraction log to the administrative workstation.

4. The method of claim 3 , wherein the third content comprises a contact header information field comprising a SIP universal resource identifier (SIP-URI) that is on a block list for the inmate calling party, and the confirmed infraction type is “call forwarding”.

5. The method of claim 3 , wherein the third content comprises a contact header information field comprising a telephone universal resource identifier (tel-URI) that is on a block list for the inmate calling party, and the confirmed infraction type is “call forwarding”.

6. The method of claim 1 , wherein the first message type is the 3xx Response, and the method further comprises sending a suspected infraction log to the administrative workstation.

7. The method of claim 6 , wherein the first content comprises contact header information comprising a SIP-URI that is on a block list for the inmate calling party, and the confirmed infraction type is “call redirect”.

8. The method of claim 6 , wherein the first content comprises contact header information comprising a tel-URI that is on a block list for the inmate calling party, and the confirmed infraction type is “call redirect”.

9. The method of claim 1 , wherein the second message type is the INVITE, and the method further comprises sending a suspected infraction log to the administrative workstation.

10. The method of claim 9 , wherein the second content comprises a contact header information field with an “isfocus” indication, and the confirmed infraction type is “call conferencing”.

11. The method of claim 9 , wherein the second content comprises a session description protocol (SDP) information section with a “a=sendonly” indication, and the confirmed infraction type is “call hold”.

12. A fraud detection system in a communication system,
the fraud detection system comprising:
a network interface device configured to receive a packet stream associated with a voice call between an inmate calling party and a called party served through Voice over Internet Protocol (VoIP) within a correctional facility; and
a processing system configured to:
determine a call phase of the voice call, wherein the call phase is one of a call setup phase and a call established phase, the call established phase occurring after a successful end of the call setup phase;
flag, during the determined call setup phase, a first session initiation protocol (SIP) message within the packet stream as suspicious based at least in part on a first message type of the first SIP message, the first message type indicating a first new party distinct from the called party and the inmate calling party, wherein the first message type is one of a 181 Response or a 3xx Response, wherein 3xx in the 3xx Response represents an integer between 300 and 399;
flag, during the determined call established phase, a second SIP message within the packet stream as suspicious based at least in part on a second message type of the second SIP message, the second message type indicating a second new party distinct from the called party and the inmate calling party, wherein the second message type is one of an INVITE or a REFER;
confirm that a fraudulent activity has occurred based at least in part on at least one of a first content of the first SIP message, a second content of the second SIP message, or a third content of a third SIP message received after the first SIP message or the second SIP message, wherein the first content, the second content, or the third content confirm that the first new party or the second new party is not allowable for the inmate calling party;
send a confirmed infraction log to an administrative workstation based on the confirming, wherein the confirmed infraction log comprises a confirmed infraction type; and
trigger a corrective operation in response to the confirming.

13. The fraud detection system of claim 12 , the processing system further configured to detect a real time protocol (RTP) packet stream between the inmate calling party and the called party, wherein the detecting indicates the successful end of the call setup phase.

14. The fraud detection system of claim 13 , the processing system further configured to flag the voice call as suspicious based on not detecting the RTP packet stream during the call established phase for a period of time exceeding a pre-determined threshold.

15. The fraud detection system of claim 12 , wherein the first message type is the 181 Response, and the processing system is further configured to send a suspected infraction log to the administrative workstation.

16. The fraud detection system of claim 15 , wherein the third content is contact header field information comprising a SIP universal resource identifier (SIP-URI) or a telephone universal resource identifier (tel-URI) that is on a block list for the inmate calling party, and the confirmed infraction type is “call forwarding”.

17. The fraud detection system of claim 12 , wherein the first message type is the 3xx Response, and the processing system is further configured to send a suspected infraction log to the administrative workstation.

Assignees

• Global Tel Link Corp

Inventors

• Hodge Stephen
• Gonzalez Eric

Classifications

• H04L63/1425

  Traffic logging, e.g. anomaly detection · CPC title

• H04L63/0236

  Filtering by address, protocol, port number or service, e.g. IP-address or URL · CPC title

• H04L63/306

  intercepting packet switched data communications, e.g. Web, Internet or IMS communications · CPC title

• H04M3/54

  Arrangements for diverting calls for one subscriber to another predetermined subscriber {(based on the calling party profile H04M3/42059; based on location H04M3/42348; based on presence H04M3/42365; to voice mail H04M3/53308)} · CPC title

• H04M7/0078 Primary

  Security; Fraud detection; Fraud prevention · CPC title