Method for Lawfully Intercepting Communication IP Packets Exchanged Between Terminals

• US 20100083364A1
• Filed: 12/18/2008
• Published: 04/01/2010
• Est. Priority Date: 09/26/2008
• Status: Active Grant

• Current Assignee: Media Patents S.L.
• Original Assignee: Media Patents S.L.
• Inventors: Fernandez Gutierrez, Alvaro
• Granted Patent: US 7,958,233 B2
• Time in Patent Office: Days
• US Class Current: 726/13
• CPC Class Codes: H04L 63/306 intercepting packet switched data communications, e.g. Web, Internet or IMS communications
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04M 3/2281 Call monitoring, e.g. for law enforcement purposes; Call tracing; Detection or prevention of malicious calls

Abstract

A method for lawfully intercepting communication IP packets exchanged between terminals is provided. The method involves assigning an IP address associated with a telecommunication service provider to, for example, a sending terminal for use as its IP address in communications with a receiving terminal, the telecommunication service provider providing SIP proxy services for establishing communication between the sending and receiving terminals. The communication IP packets are intercepted in such a way that the terminals are unaware of the interception.

Claims

1. A method for lawfully intercepting communication IP packets exchanged between a first terminal having a first IP address and a second terminal having a second IP address comprising:

a first equipment in a first data network of a first communications service provider assigning a third IP address corresponding to the first telecommunications service provider to the first terminal for use in a SDP (Session Description Protocol) connection field of SIP (Session Initiation Protocol) messages sent by the first terminal,

establishing communication between the first and second terminals by exchanging SIP messages using an SIP proxy service of the first data network,

the first equipment and/or a second equipment in the first data network receiving at least some of the communication IP packets sent from the first terminal; and

intercepting the communication IP packets in the first data network.

2. A method according to claim 1 further comprising the first equipment and/or the second equipment removing any first IP address data from the communication IP packets received from the first terminal before sending the communication IP packets to the second terminal.

3. A method according to claim 1 wherein the communication IP packets comprise SIP messages.

4. A method according to claim 1 wherein the communication IP packets comprise SIP messages and media packets.

5. A method according to claim 4 wherein the media packets are RTP (Real Time Protocol) packets.

6. A method according to claim 3 wherein the SIP messages are intercepted in the first data network without changing the SDP connection field.

7. A method according to claim 3 wherein the SIP messages include a plurality of SIP header fields and a plurality of SDP fields, the SIP messages being intercepted in the first data network without changing the third IP address in the plurality of SIP header fields and in the plurality of SDP fields.

8. A method according to claim 3 wherein the SIP messages include a plurality of SIP header fields and a plurality of SDP fields, the SIP messages being intercepted in the first data network without changing the first and third IP addresses in the plurality of SIP header fields and in the plurality of SDP fields.

9. A method according to claim 1 wherein the third IP address is associated with the first equipment.

10. A method according to claim 1 wherein the first equipment has one or more network interfaces, the third IP address being the IP address of one of the one or more network interfaces.

11. A method according to claim 1 wherein the first terminal is a Mobile Node and the first equipment is a Home Agent.

12. A method according to claim 11 wherein the Home Agent communicates with the Mobile Node using Mobile IP version 4, versions or modifications of Mobile IP version 4, or equivalents thereof.

13. A method according to claim 11 wherein the Home Agent communicates with the Mobile Node using Mobile IP version 6, versions or modifications of Mobile IP version 6, or equivalents thereof.

14. A method according to claim 1 wherein the second terminal does not belong to the first telecommunications service provider.

15. A method according to claim 1 wherein the first terminal does not belong to the first telecommunications service provider.

16. A method according to claim 1 wherein the first terminal belongs to a second telecommunications service provider and the second terminal belongs to a third telecommunications service provider, the first, second and third telecommunication service providers being different from one another.

17. A method according to claim 1 wherein the communication IP packets are intercepted by lawful intercepting equipment in the first data network which is connected to a Law Enforcement Agency.

18. A method according to claim 1 wherein the second terminal does not belong to the first telecommunications service provider, the communication IP packets being intercepted by lawful intercepting equipment in the first data network which is connected to a Law Enforcement Agency (LEA) device, the intercepting equipment receiving instructions from the LEA device to intercept the communication IP packets in a communication established by using a SIP Uniform Resource Identifier (URI) of a user of the second terminal.

19. A method according to claim 1 further comprising the first equipment and/or the second equipment in the first data network receiving SIP messages sent from the second terminal to the first terminal, at least some of the SIP messages sent from the second terminal including at least one connection field that includes the third IP address.

20. A method according to claim 19 wherein the SIP messages sent by the second terminal are intercepted in the first data network without changing the at least one SDP connection field.

21. A method according to claim 19 wherein the SIP messages sent by the second terminal include a plurality of SIP header fields and a plurality of SDP fields, the SIP messages sent by the second terminal being intercepted in the first data network without changing the third IP address in the plurality of SIP header fields and in the plurality of SDP fields.

22. A method according to claim 1 wherein the first and/or second equipment in the first data network receive from the first terminal encapsulated communication IP packets having an outer header containing the first IP address, the first and/or second equipment unpacking the encapsulated communication IP packets to remove the outer header before sending the communication IP packets to the second terminal.

23. A method for lawfully intercepting communication IP packets exchanged between a first terminal having a first IP address and a second terminal having a second IP address comprising:

a first equipment in a first data network of a first telecommunications service provider assigning a third IP address corresponding to the first telecommunications service provider to the first terminal for use in a SDP (Session Description Protocol) connection field of SIP (Session Initiation Protocol) messages sent by the first terminal,

establishing communication between the first and second terminals by exchanging SIP messages using a SIP proxy service of the first data network,

the first equipment and/or a second equipment in the first data network receiving at least some of the communication IP packets sent from the first terminal and removing any first IP address data from the communication IP packets before sending the messages to the second terminal; and

intercepting the communication IP packets in the first data network, the SIP messages being intercepted without changing the SDP connection field.

24. A method according to claim 23 wherein the communication IP packets comprise SIP messages and media packets.

25. A method according to claim 23 wherein the media packets are RTP (Real Time Protocol) packets.

26. A method according to claim 23 wherein the SIP messages exchanged between the first and second terminal include a plurality of SIP header fields and a plurality of SDP fields, the SIP messages being intercepted in the first data network without changing the third IP address in the plurality of SIP header fields and in the plurality of SDP fields.

27. A method according to claim 23 wherein the SIP messages exchanged between the first and second terminal include a plurality of SIP header fields and a plurality of SDP fields, the SIP messages being intercepted in the first data network without changing the first and the third IP addresses in the plurality of SIP header fields and in the plurality of SDP fields.

28. A method according to claim 23 wherein the third IP address is associated with the first equipment.

29. A method according to claim 23 wherein the first equipment has a network interface, the third IP address being the IP address of the network interface.

30. A method according to claim 23 wherein the first terminal is a Mobile Node and the first equipment is a Home Agent.

31. A method according to claim 30 wherein the Home Agent communicates with the Mobile Node using Mobile IP version 4, versions or modifications of Mobile IP 4, or equivalents thereof.

32. A method according to claim 30 wherein the Home Agent communicates with the Mobile Node using Mobile IP version 6, versions or modifications of Mobile IP 6, or equivalents thereof.

33. A method according to claim 23 wherein the second terminal does not belong to the first telecommunications service provider.

34. A method according to claim 23 wherein the first terminal does not belong to the first telecommunications service provider.

35. A method according to claim 23 wherein the first terminal belongs to a second telecommunications service provider and the second terminal belongs to a third telecommunications service provider, the first, second and third telecommunication service providers being different from one another.

36. A method according to claim 23 wherein the communication IP packets are intercepted by lawful intercepting equipment in the first data network which is connected to a Law Enforcement Agency device.

37. A method according to claim 23 wherein the second terminal does not belong to the first telecommunications service provider, the communication IP packets being intercepted by lawful intercepting equipment in the first data network which is connected to a Law Enforcement Agency (LEA) device, the intercepting equipment receiving instructions from the LEA device to intercept the communication IP packets in a communication established by using a SIP Uniform Resource Identifier (URI) of a user of the second terminal.

38. A method according to claim 23 further comprising the first equipment and/or the second equipment in the first data network receiving SIP messages sent from the second terminal to the first terminal, at least some of the SIP messages sent from the second terminal including at least one connection field that includes the third IP address.

39. A method according to claim 38 wherein the SIP messages sent by the second terminal are intercepted in the first data network without changing the at least one SDP connection field.

40. A method according to claim 38 wherein the SIP messages sent by the second terminal include a plurality of SIP header fields and a plurality of SDP fields, at least some of the SIP messages sent by the second terminal being intercepted in the first data network without changing the third IP address in the plurality of SIP header fields and in the plurality of SDP fields.

41. A method according to claim 23 wherein the first and/or second equipment in the first data network receive from the first terminal encapsulated communication IP packets having an outer header containing the first IP address, the first and/or second equipment unpacking the encapsulated communication IP packets to remove the outer header before sending the communication IP packets to the second terminal.

42. A method for lawfully intercepting a communication between a first terminal having a first IP address and a second terminal comprising:

sending from a first data network of a telecommunications service provider a second IP address corresponding to the telecommunications service provider for use as a source address in an inner header of at least some of the communication IP packets sent by the first terminal,

establishing communication between the first and second terminals using an SIP (Session Initiation Protocol) proxy service of the first data network, the second terminal located outside the first data network,

receiving in the first data network encapsulated communication IP packets sent from the first terminal which contain the inner header and unpacking in the first data network the encapsulated communication IP packets to remove any outer headers that contain the first IP address,

intercepting in the first data network at least some of the communication IP packets received from the first terminal without changing the inner header; and

sending from the first data network the unpacked data packets containing the inner header to the second terminal.

43. A method according to claim 42 wherein the second IP address is sent from a first server located in the first data network system.

44. A method according to claim 43 wherein the source IP address is that of a network interface of the server.

45. A method according to claim 44 wherein the source IP address is a Mobile IP version 4 or a Mobile IP version 6 address of the network interface.

46. A method according to claim 42 wherein a first server located in the first data network receives the encapsulated data packets and unpacks the data packets.

47. A method according to claim 43 wherein a second server located in the first data network and connected to the first server intercepts the communication IP packets.