Method and apparatus for session control

• US 7,590,122 B2
• Filed: 05/16/2003
• Issued: 09/15/2009
• Est. Priority Date: 05/16/2003
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Constantinof, Cristian
• Primary Examiner(s): Gauthier, Gerald
• Application Number:
  US10/439,531
• Publication Number:
  US 20040228352A1
• Time in Patent Office: 2,314 Days
• Field of Search: 370/338, 370/352, 370/242, 370/395.21, 370/431, 717/100, 709/247, 709/231, 709/219, 709/227, 709/229, 704/231, 704/247, 713/155, 713/201, 714/39
• US Class Current: 370/395.21
• CPC Class Codes: H04L 47/122 by diverting traffic away from congested entities
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/266 Stopping or restarting the source, e.g. X-on or X-off
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/745 Reaction in network
• CPC Class Codes: H04L 47/746 Reaction triggered by a failure
• CPC Class Codes: H04L 63/0227 Filtering policies mail message filtering H04L51/212
• CPC Class Codes: H04L 63/1441 Countermeasures against malicious traffic countermeasures against attacks on cryptographic mechanisms H04L9/002
• CPC Class Codes: H04L 65/1096 Supplementary features, e.g. call forwarding or call holding systems providing special services or facilities to telephony subscribers H04M3/42
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04M 3/36 Statistical metering, e.g. recording occasions when traffic exceeds capacity of trunks
• CPC Class Codes: H04M 3/367 Traffic or load control
• CPC Class Codes: H04M 7/125 Details of gateway equipment
• CPC Class Codes: H04Q 3/0091 Congestion or overload control

Abstract

The present invention provides a session filter associated with an element to be protected in a communication network. Session requests intended for the protected element are processed by the session filter prior to being forwarded to the protected element. The protected element or a device associated therewith will provide event information indicative of undesirable session conditions, such as an overload condition, which necessitates a reduction or stoppage of incoming session requests for the protected element. The session filter will directly or indirectly receive the event information and take steps to reduce or stop the session requests being sent to the protected element. The session filter may filter the incoming session requests for the protected element and selectively send select session requests to the protected element, as well as send system protection responses to minimize the number of new session requests to devices generating or forwarding the incoming session requests.

Claims

1. A method of operating a session filter device to provide session control for an element comprising:

a) receiving session requests for establishing a session between a protected element and at least one source element;

b) receiving event information indicative of an undesirable condition associated with the protected element;

c) processing the event information to determine select ones of the session requests to forward to the protected element; and

d) sending the select session requests to the protected element, wherein incoming session requests are selectively forwarded to the protected element upon receipt of the event information.

2. The method of claim 1 further comprising sending a system protection response configured to stop or reduce a number of the session requests from being generated by the at least one source element.

3. The method of claim 2 wherein the system protection response is sent to the at least one source element.

4. The method of claim 2 wherein the system protection response is sent to a session filter associated with the at least one source element.

5. The method of claim 2 wherein the event information is sent to a session filter associated with the at least one source element.

6. The method of claim 2 wherein the session requests are received via a packet network and the system protection response is sent over a call signaling network for a circuit-switched network.

7. The method of claim 2 wherein the session requests are received via a call signaling network for a circuit-switched network and the system protection response is sent over a packet network.

8. The method of claim 1 wherein the session request is a call setup message from a circuit-switched network.

9. The method of claim 1 wherein the session request is a session initiation protocol INVITE message from a session initiation protocol network.

10. The method of claim 1 wherein the event information is received from the protected element.

11. The method of claim 1 wherein the event information is received from an entity other than the protected element.

12. The method of claim 1 wherein the event information is indicative of an overload condition for the protected element.

13. The method of claim 1 wherein the event information is indicative of a network failure affecting the protected element.

14. The method of claim 1 wherein the event information is indicative of a malicious session request attack for the protected element.

15. The method of claim 1 wherein the event information further provides information to assist in determining the select session requests.

16. The method of claim 1 wherein the event information provides information identifying the at least one source element from which the session requests are filtered.

17. The method of claim 1 wherein the event information further provides information in the group consisting of:

a) information indicative of a number of the session requests that can be forwarded to the protected element;

b) information indicative of a desired reduction in the session requests forwarded to the protected element; and

c) information indicative of a number of sessions capable of being supported by the protected element.

18. The method of claim 1 wherein for certain event information all session requests for the protected element are blocked.

19. A session filter for providing session control for an element comprising:

a) at least one interface; and

b) a control system associated with the at least one interface and adapted to;

i) receive session requests for establishing a session between a protected element and at least one source element;

ii) receive event information indicative of an undesirable condition associated with the protected element;

iii) process the event information to determine select ones of the session requests to forward to the protected element; and

iv) send the select session requests to the protected element,

wherein incoming session requests are selectively forwarded to the protected element upon receipt of the event information.

20. The session filter of claim 19 wherein the control system is further adapted to send a system protection response configured to stop or reduce a number of the session requests from being generated by the at least one source element.

21. The session filter of claim 20 wherein the system protection response is sent to the at least one source element.

22. The session filter of claim 20 wherein the system protection response is sent to a session filter associated with the at least one source element.

23. The session filter of claim 20 wherein the event information is sent to a session filter associated with the at least one source element.

24. The session filter of claim 20 wherein the session requests are received via a packet network and the system protection response is sent over a call signaling network for a circuit-switched network.

25. The session filter of claim 20 wherein the session requests are received via a call signaling network for a circuit-switched network and the system protection response is sent over a packet network.

26. The session filter of claim 19 wherein the session request is a call setup message from a circuit-switched network.

27. The session filter of claim 19 wherein the session request is a session initiation protocol INVITE message from a session initiation protocol network.

28. The session filter of claim 19 wherein the event information is received from the protected element.

29. The session filter of claim 19 wherein the event information is received from an entity other than the protected element.

30. The session filter of claim 19 wherein the event information is indicative of an overload condition for the protected element.

31. The session filter of claim 19 wherein the event information is indicative of a network failure affecting the protected element.

32. The session filter of claim 19 wherein the event information is indicative of a malicious session request attack for the protected element.

33. The session filter of claim 19 wherein the event information further provides information to assist in determining the select session requests.

34. The session filter of claim 19 wherein the event information provides information identifying the at least one source element from which the session requests are filtered.

35. The session filter of claim 19 wherein the event information further provides information in the group consisting of:

a) information indicative of a number of the session requests that can be forwarded to the protected element;

b) information indicative of a desired reduction in the session requests forwarded to the protected element; and

c) information indicative of a number of session requests capable of being supported by the protected element.

36. The session filter of claim 19 wherein for certain event information all session requests intended for the protected element are blocked.

37. A method of operating a session filter device to provide session control for an element comprising:

a) receiving session requests for establishing a session between a protected element and at least one source element;

b) receiving event information indicative of an undesirable condition associated with the protected element;

c) processing the event information to determine select ones of the session requests; and

d) sending a system protection response configured to stop or reduce a number of the session requests from being generated by the at least one source element.

38. The method of claim 37 further comprising sending the select session requests to the protected element wherein incoming session requests are selectively forwarded to the protected element upon receipt of the event information.

39. A session filter for providing session control for an element comprising:

a) at least one interface; and

b) a control system associated with the at least one interface and adapted to;

i) receive session requests for establishing a session between a protected element and at least one source element;

ii) receive event information indicative of an undesirable condition associated with the protected element;

iii) process the event information to determine select ones of the session requests; and

iv) send a system protection response configured to stop or reduce a number of the session requests from being generated by the at least one source element.

40. The session filter of claim 39 wherein said control system is further adapted to send the select session requests to the protected element wherein incoming session requests are selectively forwarded to the protected element upon receipt of the event information.