PRIORITIZING LAWFUL INTERCEPT SESSIONS

• US 20120317273A1
• Filed: 06/13/2011
• Published: 12/13/2012
• Est. Priority Date: 06/13/2011
• Status: Active Grant

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: SHANKARAPPA, Divakar
• Granted Patent: US 8,601,118 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 47/821 Prioritising resource allocation or reservation requests
• CPC Class Codes: H04M 2201/14 Delay circuits; Timers
• 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 may include receiving a request for a lawful intercept (LI) session, where the LI session is associated with a particular priority of a set of priority levels, and determining whether a maximum quantity of LI sessions has been initiated by a network device. The method may further include initiating a new LI session based on the request, when the maximum quantity of LI sessions has not been initiated; determining whether at least one LI session exists that is associated with a lower priority than the particular priority, when the maximum quantity of LI sessions has been initiated; and terminating a particular LI session associated with a lowest priority and initiating a new LI session based on the received request, when the at least one LI session associated with the lower priority exists.

Claims

1. A method performed by a network device, the method comprising:

receiving, by the network device, a request for a lawful intercept (LI) session, where the LI session is associated with a particular priority of a set of priority levels;

determining, by the network device, whether a maximum quantity of LI sessions has been initiated by the network device;

initiating, by the network device, a new LI session based on the request, when the maximum quantity of LI sessions has not been initiated;

determining, by the network device, whether at least one LI session exists that is associated with a lower priority than the particular priority, when the maximum quantity of LI sessions has been initiated;

terminating, by the network device, a particular LI session associated with a lowest priority, when the at least one LI session associated with the lower priority exists;

initiating, by the network device, a new LI session based on the received request, in response to terminating the particular LI session associated with the lower priority; and

dropping, by the network device, the received request without initiating a new LI session, when the at least one LI session associated with the lower priority does not exist.

2. The method of claim 1, further comprising:

informing a law enforcement agency associated with the terminated particular LI session that the particular LI session has been terminated.

3. The method of claim 1, where the set of priority levels includes a low priority level and a high priority level.

4. The method of claim 1, where the set of priority levels includes a low priority level, a medium priority level, and a high priority level.

5. The method of claim 1, further comprising:

selecting a set of existing LI sessions associated with the lowest priority;

determining whether there exists at least one LI session with an invalid target in the selected set of existing LI sessions; and

selecting the at least one LI session with the invalid target as the particular LI session to terminate.

6. The method of claim 1, further comprising:

selecting a set of existing LI sessions associated with the lowest priority;

determining whether there exists at least one LI session in an idle state in the selected set of existing LI sessions; and

selecting an LI session associated with a longest idle time as the particular LI session to terminate, when there exists at least one LI session in an idle state in the selected set of existing LI sessions.

7. The method of claim 6, further comprising:

selecting an LI session associated with an oldest initiation timestamp, from the selected set of existing LI sessions, as the particular LI session to terminate, when there does not exist at least one LI session in an idle state in the selected set of existing LI sessions.

8. The method of claim 1, where the network device includes a packet data network gateway of a Long Term Evolution access network.

9. A network device comprising:

a memory to store lawful intercept (LI) session records associated with existing LI sessions of the network device; and

a processor to;

monitor packets based on the stored LI records;

receive a request for an LI session, where the LI session is associated with a particular priority of a set of priority levels;

determine whether a maximum quantity of LI sessions, of the stored LI session records, has been initiated by the network device;

initiate a new LI session based on the request, when the maximum quantity of LI sessions has not been initiated;

determine whether at least one LI session exists, in the stored LI session records, that is associated with a lower priority than the particular priority, when the maximum quantity of LI sessions has been initiated;

terminate a particular LI session, in the stored LI session records, associated with a lowest priority, when the at least one LI session associated with the lower priority exists;

initiate a new LI session based on the received request, in response to terminating the particular LI session associated with the lower priority; and

drop the received request without initiating a new LI session, when the at least one LI session associated with the lower priority does not exist.

10. The network device of claim 9, where the processor is further to:

select a set of existing LI sessions, from the stored LI session records, associated with the lowest priority;

determine whether there exists at least one LI session with an invalid target in the selected set of existing LI sessions; and

select the at least one LI session with the invalid target as the particular LI session to terminate.

11. The network device of claim 9, where the processor is further to:

select a set of existing LI sessions, from the stored LI session records, associated with the lowest priority;

determine whether there exists at least one LI session in an idle state in the selected set of existing LI sessions; and

select an LI session associated with a longest idle time as the particular LI session to terminate, when there exists at least one LI session in an idle state in the selected set of existing LI sessions.

12. The network device of claim 11, where the processor is further to:

select an LI session associated with an oldest initiation timestamp, from the selected set of existing LI sessions, as the particular LI session to terminate, when there does not exist at least one LI session in an idle state in the selected set of existing LI sessions.

13. The network device of claim 9, where the network device includes a packet data network gateway of a Long Term Evolution access network.

14. The network device of claim 9, where the network device includes at least one of a Mobility Management Entity, a Serving Gateway, or a Policy and Charging Rules Function of a Long Term Evolution access network.

15. The network device of claim 9, where the network device includes a General Packet Radio Service node.

16. The network device of claim 9, where the network device includes a Call Session Control Function of an Internet Protocol Multi-media Subsystem.

17. A non-transitory computer-readable medium storing instructions executable by one or more processors, the non-transitory computer-readable medium comprising:

one or more instructions to receive a request for a lawful intercept (LI) session, where the LI session is associated with a particular priority of a set of priority levels;

one or more instructions to determine whether a maximum quantity of LI sessions has been initiated by the network device;

one or more instructions to initiate a new LI session based on the request, when the maximum quantity of LI sessions has not been initiated;

one or more instructions to determine whether at least one LI session exists that is associated with a lower priority than the particular priority, when the maximum quantity of LI sessions has been initiated;

one or more instructions to terminate a particular LI session associated with a lowest priority, when the at least one LI session associated with the lower priority exists;

one or more instructions to initiate a new LI session based on the received request, in response to terminating the particular LI session associated with the lower priority; and

one or more instructions to drop the received request without initiating a new LI session, when the at least one LI session associated with the lower priority does not exist.

18. The non-transitory computer-readable medium of claim 17, further comprising:

one or more instructions to select a set of existing LI sessions associated with the lowest priority;

one or more instructions to determine whether there exists at least one LI session with an invalid target in the selected set of existing LI sessions; and

one or more instructions to select the at least one LI session with the invalid target as the particular LI session to terminate.

19. The non-transitory computer-readable medium of claim 17, further comprising:

one or more instructions to select a set of existing LI sessions associated with the lowest priority;

one or more instructions to determine whether there exists at least one LI session in an idle state in the selected set of existing LI sessions; and

one or more instructions to select an LI session associated with a longest idle time as the particular LI session to terminate, when there exists at least one LI session in an idle state in the selected set of existing LI sessions.

20. The non-transitory computer-readable medium of claim 19, further comprising:

one or more instructions to select an LI session associated with an oldest initiation timestamp, from the selected set of existing LI sessions, as the particular LI session to terminate, when there does not exist at least one LI session in an idle state in the selected set of existing LI sessions.