The subject matter described herein relates to the monitoring of ping calls and preventing fraudulent activities within a communications network. More particularly, the subject matter described herein relates to methods, systems, and computer program products for detecting and mitigating ping call events in a communications network.
Presently, fraudsters and other unscrupulous parties are taking advantage of inherencies existing in telecommunications networks to conduct fraudulent or unethical activities. Specifically, some fraudsters are manipulating subscribers' caller ID displays and missed call logs by using ping calls (i.e., calls that are quickly released upon connecting with a called party terminal) to compel unsuspecting victims to call back. In one scenario, ping calls are used to inflate revenues for premium rate services (PRS). For example, a fraudster may use one or more automatic dialers positioned behind a private branch exchange (PBX) to transmit multiple call signaling messages into a particular geographic area, wherein each call is directed to a different called party. However, before a call can be answered by a recipient, the call is released by the PBX and a calling party number is captured by the caller ID display or missed call log.
In these ping call event scenarios, the captured calling party number is typically a “spoofed” calling party number. Namely, the fraudster replaces the Automatic Number Identification (ANI) number (i.e., the original calling party number) for each call with some other number that does not raise suspicion on the called party's caller ID display or log of missed calls. However, the spoofed number may be associated with a PRS call center or operator. In many instances, this results in the called party dialing the captured ANI number back after realizing a call has been missed. The return call is then routed to a PRS operator. Although the caller (i.e., the original called party) normally hangs up immediately after realizing a PRS call center has been reached, the call has already been made, (i.e., the connection to the PRS operator has been completed) and charges have been assessed. In many instances, the rates for connecting the call are significant and may be assessed to the unsuspecting called victim. In other cases, the connecting operator may be held responsible for paying the PRS operators for these calls. Revenues collected by PRS operators obtained in this unethical manner can amount to millions of dollars per year.
In a similar scenario, ping calls are used by telemarketers in the United States as a means for bypassing the “Do Not Call” registry. The process for attracting an unsuspecting victim is the same as described above. Namely, one or more automatic dialers are used to launch hundreds or thousands of calls into the network that are released after sufficient time for false caller ID information to be displayed. The unsuspecting called parties then return the call and reach a telemarketer operator. No immediate revenue loss is associated with this scenario, other than those associated with possible congestion at the switches and trunks.
Accordingly, there exists a need for methods, systems, and computer program products for detecting and mitigating ping call events in a communications network.
According to one aspect, the subject matter described herein comprises methods, systems, and computer program products for detecting and mitigating a ping call event in a communications system. One method includes receiving a plurality of call signaling messages. The plurality of call signaling messages are analyzed and a determination is made as to whether at least a portion of the plurality of call signaling messages indicates a ping call event. In response to determining that the at least a plurality of call signaling messages indicates a ping call event, a mitigating action is performed.
The subject matter described herein for detecting and mitigating a ping call events may be implemented using a computer program product comprising computer executable instructions embodied in a computer readable medium that are executed by a computer processor. Exemplary computer readable media suitable for implementing the subject matter described herein includes disk memory devices, programmable logic devices, application specific integrated circuits, and downloadable electrical signals. In addition, a computer readable medium that implements the subject matter described herein may be distributed across multiple physical devices and/or computing platforms.
Preferred embodiments of the subject matter described herein will now be explained with reference to the accompanying drawings of which:
The present subject matter relates to systems, methods, and computer program products for detecting and mitigating ping call events in a communications network. In order to better understand the present subject matter, an explanation regarding the manner in which a communications network can be exploited using a ping call event is presented below. As used herein, a ping call event is characterized as a large volume of calls placed into the network by a fraudster or telemarketer using one or more automated dialers positioned behind a private branch exchange (PBX). The calls are called “ping calls” because they are released before the called party is able answer.
Upon receiving call initiation signal 120, PBX 104 generates a call signaling message (e.g., IAM message 121) addressed to the called party number (CdPN) associated with targeted subscriber 1161 and containing a calling party number (CgPN) associated with PBX 104. Call signaling message 121 is then routed to an intermediate switching point that is complicit with the fraudulent ping call event scheme. In
After being modified with the spoofed CgPN, IAM message 123 is routed from softswitch 106 to the network (e.g., customer network 101) that supports the subscriber corresponding to the targeted CdPN (e.g., subscriber 1161). In this example, IAM message 123 enters customer network 101 via gateway signal transfer point (STP) 110. Gateway STP 110 routes IAM message 123 to a terminating switch 112, which is responsible for serving targeted subscriber 1161. Upon receiving IAM message 123, terminating switch 112 responds to softswitch 106 with an ACM message 124, and applies a ringtone to the line of subscriber 1161.
At approximately the same time that target terminal 116 is alerted of the call, PBX 104 receives ACM message 122 from softswitch 106 and (in response to receiving ACM 122) waits for a short predefined period of time (e.g., 1 to 5 seconds) before generating and transmitting a release message 125. PBX 104 may be configured by the fraudster to send release message 125 to initiate the teardown of the call since there was never any intention for the ping call to be answered. Specifically, release message 125 is transmitted to softswitch 106, which then releases the reserved bearer trunk/circuit and responds to PBX 104 with a release complete (RLC) message 126. Softswitch 106 subsequently generates a release message 127, which is transmitted to terminating switch 112. Terminating switch 112 releases the reserved bearer trunk/circuit for that leg of the call and transmits its own RLC message 128 to softswitch 106 thereby ending the call. However, before the call is ended, the spoofed calling party number has already been captured by the called party's caller ID display or missed call log. The capture of the spoofed calling party number by the targeted subscriber is important since the fraudster relies on the targeted subscriber to ultimately notice the spoofed CgPN number as a missed call and to subsequently choose to call the spoofed CgPN. Although it is likely that most people do not return a call to an unfamiliar number, the fraudster is still able to deceive (i.e., “hook”) a considerable number of people due to the sheer number of ping calls made.
In order to detect and mitigate ping call events that deceive callers to contact fraudulent or telemarketing entities, the present subject matter includes a ping call detection system (PCDS).
In an alternate embodiment, PCDS 150 may be implemented as a PCDS module within gateway STP 110 as shown in
When a signaling message is received by STP 110, the message may be processed by LIM 510, DCM 506, or HSL 508 depending on whether the message is sent over an SS7 link, an IP signaling link, or a high speed link. The message is passed up the communications protocol stack on the receiving communication module until it reaches the module's respective message distribution function, which forwards the call signaling message to DSM 522. In one embodiment, at least one DSM module 522 in STP 110 is equipped with a PCDS module. In one embodiment, the PCDS module functions in a similar manner to the PCDS depicted and described in
In addition to collecting signaling data, PCDS 150 (either as a stand-alone network component or integrated in STP 110) may be responsible for analyzing the received call signaling data. In one embodiment, PCDS 150 is configured with at least one filter that is used to detect certain call characteristics that may be indicative of a ping call event. For example, an exemplary ping call event may be characterized as including a large volume of inbound calls originated by one source (or very few sources) and terminating at plural sources. Similarly, the calls associated with the ping call event are may be characterized as having been released by the originator after a short duration (e.g., 1-5 seconds). The ping call event may also cause trunks and/or routes in customer network 101 to reach a state of congestion.
These characteristics, or key parameters, may be used as criteria by a PCDS filter to objectively detect a ping call event. In one embodiment, a filter is generated by quantifying one or more characteristics with a respective threshold. For example, a threshold including a predefined number of inbound calls from a single source over a certain period of time (e.g., 20 calls over 60 seconds from the same CgPN) may be used as a threshold component for a filter. This filter component may be used to detect calls placed in a rapid succession, as one might expect from an automatic machine dialer. Similarly, one filter threshold component may utilize an answer seizure ratio (ASR) that monitors the number of attempted calls that are ultimately completed. Specifically, ASR includes the ratio of the number of attempted calls to the number of calls that are picked up by the called party. Since a ping call is intended to leave a spoofed CgPN on a caller ID display (or missed called log) before the call is answered, a high ASR ratio (e.g., a 50:1 ratio) may be indicative of a ping call event. Likewise, a filter component may include a threshold that detects a high quantity of short length calls released by the originator (e.g., more than 50 calls lasting up to 5 seconds and are terminated by the calling party). Once a filter is created, it may be applied by PCDS 150 to any received call signaling message stream or copy thereof. In one embodiment, if one or more of the filter threshold components are exceeded (as configured by a network operator), then an indication is given that a potential ping call event may be detected.
In block 604, the call signaling messages are analyzed. In one embodiment, PCDS 150 utilizes a screening and mitigation module 422 to apply filters to the received call signaling messages. Specifically, screening and mitigation module 422 uses filters to determine various call characteristics.
In block 606, a determination is made as to whether a ping call event is detected. In one embodiment, data analysis module 414 analyzes the filter results to determine if a possible ping call event exists. For example, if a predefined number of filter thresholds are exceeded, then a possible ping call event is detected. If a possible ping call event exists, then method 600 continues to block 608. If a ping call event is not suspected, then method 600 loops back to block 602 to continue monitoring.
In block 608, a mitigating action is performed. In response to detecting a ping call event, PCDS 150 may perform a mitigation action. In one embodiment, PCDS 150 is configured to modify the calling party number of the signaling messages associated with the ping call event. For example, a network operator's phone number may be used to replace the spoofed CgPN. In an alternate embodiment, PCDS 150 is adapted to block the call by releasing call signaling messages associated with the detected ping call event so that the called party never receives the ping call. The method 600 then ends.
As mentioned above, PCDS 150 may be configured to perform a mitigating action such as generating an alarm, blocking calls, producing dashboards, and outputting reports. For example, when a ping call event occurs and is detected by PCDS 150, a network operator may receive an alarm at NOC 119 indicating the ping call event is occurring (in real-time). Upon receiving the alarm, the operator may analyze the filtered data to confirm the occurrence of the detected ping call event. The alarm may also identify the origin of the ping call event so that other mitigating actions may be performed.
In one embodiment, PCDS 150 may generate one or more dashboards to provide a network operator a real-time condition of the network as well as statistics on ping call events. The purpose of the dashboard is used to alert the security department that a ping call attack may be underway, but has not yet reached congestion points. In one embodiment, the dashboards measure the number of short duration calls within the network, and when the number of short duration calls reach a threshold level, the dashboards indicate this through a graphical indicator. In one embodiment, traffic level dashboards provide an overall graph of traffic levels across all inbound routes allowing the operator to monitor traffic levels as well as highlighting increases that appear to be anomalies. This proactive view of attacks alerts the operator that the network traffic flows are beginning to reach critical levels.
In one embodiment, PCDS 150 may be configured to block the ping calls upon detection. An exemplary gateway STP-based PCDS adapted for active blocking is depicted in
After a ping call event is initially suspected, PCDS 150 may generate an alarm message 160 to network operations center (NOC) 119. In response, NOC 119 establishes a call blacklist that may be implemented at STP 110 (or some other node in customer network 101). For example, any received call with a CgPN matching any one of the CgPN entries in the call blacklist is actively blocked. In one embodiment, the blocking action may include receiving and detecting a blacklisted IAM at STP 110 (e.g., receiving IAM message 703), discarding the IAM, and generating a release message (e.g., release message 704) back to the originating switch. The call blacklist may include any number of calling party numbers (e.g., PBX_PRS) so as to block a single CgPN or range of CgPN numbers that may be used by the fraudster. In another embodiment, a network operator or PCDS 150 may block all calls coming from an SS7 or IP network address associated with an originating/offending switch instead of using calling party numbers. This feature may be implemented at the gateway screening level of STP 110.
In one embodiment, PCDS 150 is adapted to modify IAM messages upon detecting a ping call event. An exemplary gateway STP-based PCDS adapted for calling party number modification is depicted in
Consequently, the “calling party number” captured by the targeted subscriber's telephone or caller ID unit is no longer the spoofed CgPN, but instead is a number associated with the network operator, a network call center, or a network operator controlled/authorized IVR. This is shown in IAM message 803, which includes a replacement CgPN (i.e., operator or IVR) and the spoofed CgPN (i.e., PRS-POTS) in the GAP field. Therefore, if the targeted subscriber is “hooked” and happens to return the call to the CgPN left on the caller ID display (or in the missed call log), a network operator or IVR service is reached instead. The network operator or authorized IVR service associated with customer network 101 may then bring the subscriber's attention to the suspicious nature of the call-back number that was replaced and confirm whether the subscriber wishes to proceed to contact the original calling party.
In yet another embodiment, PCDS 150 may identify a call attempt as a potential ping call, and subsequently re-direct the call to an intermediate network operator controlled IVR element. The IVR element is adapted to answer the call and confirm the validity of the calling party. For example, the IVR may answer the call and request that the calling party enter a digit sequence in order to continue call setup to the original called party. If the calling party (e.g., a ping call machine dialer) is unable to comply with the request, then the call may be interpreted as a ping call and an appropriate mitigating action may be taken by the network operator. If the calling party is able to comply with the validation request, then the IVR is adapted to continue call setup to the original called party.
In the examples illustrated above, PCDS 150 is configured as a probe-based system (
After receiving the SIP INVITE message (but before the called party answers), SIP call device 136 transmits a “180 message” (i.e., a “trying to contact” message) back to machine dialer 102 via SIP proxy 143 and SIP proxy 145. In response, machine dialer 102 sends a Cancel message (e.g., a release message) back to SIP call device 136 (via SIP proxy 143 and SIP proxy 145). Upon receiving the Cancel message, call device 136 releases the call. Like the aforementioned examples, the release action is typically executed prior to the called party answering the phone but after the spoofed calling party URI (e.g., PRS_URI) is captured by the caller ID function or missed call log associated with SIP call device 136.
In one embodiment, SIP proxy 145 may include PCDS 150, which is adapted to perform all SIP-based ping call event monitoring and mitigating functions. The SIP-based monitoring and mitigating functions are performed in a manner similar to the STP based ping call event monitoring and mitigating functions described above.
It will be understood that various details of the subject matter described herein may be changed without departing from the scope of the subject matter described herein. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation, as the subject matter described herein is defined by the claims as set forth hereinafter.
The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/964,334, filed Aug. 10, 2007; the disclosure of which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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60964334 | Aug 2007 | US |