Secure detection of an intercepted targeted IP phone from multiple monitoring locations

• US 6,496,483 B1
• Filed: 08/18/1999
• Issued: 12/17/2002
• Est. Priority Date: 08/18/1999
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Russell, Jesse Eugene, Wang, Spencer C., Sankalia, Anish, Kung, Fen-Chung
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Tran, Maikhanh
• Application Number:
  US09/376,459
• Time in Patent Office: 1,217 Days
• Field of Search: 370/389-390, 370/392, 370/352, 370/259-264, 370/401, 370/252, 370/465-469, 379/32.01, 379/35, 379/67.1, 379/70, 379/133, 379/88.01, 379/88.02, 379/88.19, 379/207.02, 379/219, 379/220.01
• US Class Current: 370/252
• CPC Class Codes: H04L 41/28 Restricting access to network management systems or functions, e.g. using authorisation function to access network configuration
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 63/083 using passwords cryptographic mechanisms or cryptographic arrangements for entity authentication using a predetermined code H04L9/3226
• CPC Class Codes: H04M 3/2281 Call monitoring, e.g. for law enforcement purposes; Call tracing; Detection or prevention of malicious calls
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42

Abstract

Secure monitoring of a target IP telephone may be obtained simultaneously at a plurality of monitoring stations by requiring authentication to be provided by each of the monitoring stations prior to granting access permission to monitor the call. A single request generates multiple duplicate calls to a plurality of different monitoring location, each of which must be authenticated. When the monitored call arrives at each of the multiple monitoring stations a password is used to achieve authentication permission. The password is entered at each monitoring station by a touchtone keypad that generates Dual Tone Multi-frequency (DTMF) signals (e.g., each signal is a combination of two tones at different frequencies) which is sent to an IP monitoring center, which grants surveillance permission.

Claims

1. A method of secure surveillance of a target IP telephone from a plurality of monitoring stations;

comprising the steps of;

initiating a request for surveillance of a target IP telephone from one of a plurality of surveillance stations each of which may be serviced by a network of different technology from those of other surveillance stations;

generating a plurality of duplicate calls to each of the plurality of monitoring stations in response to the initiating a request;

authenticating each of the monitoring stations seeking to join in the surveillance by entry of a password for each monitoring station;

muting the duplicate calls from any of the monitoring stations not having achieved authentication; and

formatting intercepted messages of the monitored target IP phone for conforming to delivery over networks having a different technology than that of the target IP telephone by;

establishing a database of monitoring stations and a technology of their connecting networks at a central monitoring center associated with the IP network of the target IP telephone.

2. The method of claim 1, wherein the entry of a password includes a step of:

generating a Dual Tone Multi-Frequency (DTMF) signal by means of a keyboard entry.

3. The method of claim 2 further including wherein a step of:

transmitting the DTMF signal to an IP monitoring center, which is operative to grant surveillance intercept permission.

4. A surveillance system for the monitoring of a target IP telephone from a plurality of monitoring stations, comprising:

a first and second monitoring station, each connected to at least one of a plurality of telephone networks;

a target IP telephone connected to a specific one of the plurality of telephone networks;

an IP Address Mapping Check Point (IP-AMCP) connected to service at least the specific one of the plurality of telephone networks by determining a voice signal type to be forwarded to each of the monitoring stations and further including a WatchDog function to identify activity of the target IP telephone; and

an IP monitoring center connected to interconnect monitoring stations connected to a different network from the specific one of the plurality of telephone networks to the specific one of the plurality of telephone networks.

5. The surveillance system of claim 4, further comprising:

an IP Phone Intercept List (IP-PIL) included with the IP-AMCP for maintaining a database of target telephones to be monitored.

6. The surveillance system of claim 4, wherein the specific one of the plurality of telephone networks is an IP network.

7. The surveillance system of claim 6, wherein at least one of the at least one of a plurality of telephone networks is a PSTN system.

8. The surveillance system of claim 7, further including:

a PSTN Check Point (PCP) connected between the PSTN system and the IP monitoring center for translating between IP and PSTN signal formats.