Method and apparatus for dynamically routing calls in an intelligent network

• US 6,226,289 B1
• Filed: 09/29/1997
• Issued: 05/01/2001
• Est. Priority Date: 09/24/1997
• Status: Expired due to Term

• Current Assignee: Broadview Networks Incorporated (Windstream Holdings II LLC)
• Original Assignee: Bell Canada (BCE Incorporated)
• Inventors: Clermont, Normand A., Williams, L. Lloyd, Reid, Colin A.
• Primary Examiner(s): VU, HUY DUY
• Application Number:
  US08/939,909
• Time in Patent Office: 1,310 Days
• Field of Search: 370/351, 370/352, 370/522, 370/384, 370/385, 370/381, 370/382, 370/383, 379/219, 379/220, 379/221, 379/222, 379/223, 379/224, 379/229, 379/230, 379/231, 379/232, 379/233, 379/234, 379/201, 379/210, 379/211, 379/212, 340/825.03, 340/827
• US Class Current: 370/385
• CPC Class Codes: H04Q 3/0029 Provisions for intelligent networking

Abstract

A method, apparatus and system for dynamically routing selected calls through an intelligent switched telephone network are described. The method leverages the resident switching power in the Public Switched Telephone Network by departing from the Advanced Intelligent Network (AIN) call model while adhering to the basic principles of ISUP common channel signaling to introduce new flexibility in call routing. Using the method, calls can be efficiently routed and rerouted through the network. Control of a call can be effected by either the called party or the calling party. The method can be practised using either a virtual switching point (VSP) or an ISTP. The VSP is a physical mode in the signaling plane of the network and a virtual node in the switching plane. Calls are routed to the VSP using dedicated trunk groups which may be loop-back ISUP trunks or inter-switch ISUP trunks. Calls are routed to the dedicated trunk groups using standard routing translation tables and methods. The advantage is a new level of flexibility in call routing control that permits the rapid introduction of new services which include features that could not be efficiently accommodated using prior methods of call routing.

Claims

1. A method of dynamically routing selected calls through an intelligent switched telephone network using common channel signaling messages generated by a call control node in the common channel signaling control path for the call, comprising the steps of:

a) routing a call through the network to a first termination in response to a number dialed by a calling party so that the common channel signaling path for the call passes through the call control node;

b) receiving at the call control node an indication that a predetermined criteria related to the call has been met;

c) determining at the call control node a new termination for the call indicated directly or indirectly by the predefined criteria;

d) initiating a release of the first termination using at least one common channel signaling message generated by the call control node without releasing the calling party;

e) initiating the rerouting of the call to the new termination using at least one common channel signaling message generated by the call control node; and

f) repeating steps b)-e) until the call is terminated.

2. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 1 wherein the call control node is a virtual switching point comprising:

a common channel signaling interface for receiving and sending common channel signaling messages;

means for examining common channel signaling messages and transparently passing selected common channel signaling messages to an adjacent signaling node;

means for generating common channel signaling messages in response to predetermined criteria; and

means for tracking individual calls virtually switched therethrough.

3. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 2 wherein the virtual switching point further comprises:

a data interface for receiving data inputs from a data network other than the common channel signaling network of the switched telephone network.

4. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 3 wherein the data inputs are call tracking messages.

5. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 3 wherein the data inputs are call control messages.

6. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 2 wherein the virtual switching point further comprises:

means for translating dialed numbers into call routing information.

7. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 4 wherein the means for translating is enabled to translate dialed digits into call routing information based on a value of at least one predefined variable.

8. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 7 wherein the at least one predefined variable includes time of day and day of week.

9. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 1 wherein the network node is an Intelligent Signal Transfer Point (ISTP).

10. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 1 wherein the call control node is a virtual switching point and the selected calls are routed so that the common channel signaling control path passes through the virtual switching point by:

designating at least one trunk connected to at least one switching node in the switched telephone network as a trunk group to which the selected calls are routed;

creating routing table entries in the at least one switching node to route the selected calls to the at least one trunk group; and

creating a linkset and routeset so that common channel signaling messages related to calls routed to the at least one trunk group are routed to the virtual switching point.

11. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 10 wherein the at least one trunk is a loop-back trunk having an outbound end and a inbound end respectively connected to a trunk side of the at least one network switching node.

12. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 11 wherein the outbound end and the inbound end are respectively assigned sequential circuit identification codes.

13. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 10 wherein the at least one trunk is an inter-switch trunk.

14. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 1 wherein the selected calls are routed based on dialed digits.

15. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 14 wherein the dialed digits are translated at a Service Control Point before routing occurs.

16. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 1 wherein the selected calls are routed based on calling line identification.

17. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 1 wherein the selected calls are routed based on calling line identification and dialed digits.

18. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 1 wherein the call control node passes only selected common channel signaling messages back towards an originating end of a call until the call is disconnected.

19. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 18 wherein the common channel signaling messages are Signaling System 7 (SS7) ISDN User Part (ISUP) messages.

20. A method of dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 18 wherein the selected common channel signaling messages comprise Initial Address Message (IAM). Address Complete Message (ACM), Answer Message (ANM) Release (REL) and Release Complete (RLC) messages.

21. An apparatus for dynamically routing selected calls through an intelligent switched telephone network comprising:

a common channel signaling interface for receiving messages from and sending messages to a common channel signaling network, the common channel signaling interface being assigned a service switching point code so that the apparatus appears in the switched telephone network as a switching point (SP);

a memory for storing at least one of the common channel signaling messages;

a memory for storing programs enabling a processor to examine common channel signaling messages received at the common channel signaling interface, generate common channel signaling messages for controlling call connections, tracking calls virtually routed through the switching point (SP), and assessing predefined criteria to determine an action respecting the control of call connections; and

processor means for executing the programs.

22. An apparatus for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 21 wherein the apparatus further includes a connection to a data network other than the common channel signaling network.

23. An apparatus for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 22 wherein an Intelligent Peripheral is also connected to the data network and the Intelligent Peripheral exchanges messages over the data network with the apparatus.

24. An apparatus for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 22 wherein a call center is also connected to the data network and the call center exchanges messages over the data network with the apparatus.

25. An apparatus for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 21 wherein the programs are further enabled to pass on certain common channel signaling messages received at the common channel signaling interface.

26. An apparatus for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 25 wherein at least some of the messages passed on are modified before they are re-emitted into the common channel signaling network.

27. An apparatus for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 26 wherein the messages that are modified are modified only to an extent that the Originating Point Code and the Destination Point Code is changed to appear logically correct at a node that is a recipient of the message.

28. A system for dynamically routing selected calls through an intelligent switched telephone network, comprising:

a call control node in a common channel signaling network of the intelligent switched telephone network;

means for routing selected calls so that a common channel signaling control path for the selected calls passes through the call control node;

an Intelligent Peripheral (IP) connected to the intelligent switched telephone network, the IP being adapted to respond to caller inputs from the selected calls; and

a data connection that links the call control node and the IP, whereby when a common channel signaling path for one of the selected calls is completed through the call control node and the call is terminated at the IP, the IP is enabled to collect inputs from a calling party and pass data over the data connection to the call control node to permit the call control node to release the call in a forward direction and to reconnect the call to a new termination specified by the data without releasing the calling party.

29. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 28 wherein the IP is an Interactive Voice Response unit.

30. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 28 wherein the call control node is a virtual switching point in the network.

31. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 28 wherein the call control node is an Intelligent Signal Transfer Point (ISTP).

32. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 30 wherein the means for routing selected calls so that a common channel signaling control path for the selected calls passes through the network comprises:

at least one trunk connected on at least one end to a switching node in the network, the at least one trunk being designated as a trunk group to which the selected calls are routed in that switching node;

creating routing table entries in the switching node to route the selected calls to the at least one trunk group; and

creating a linkset and routeset so that common channel signaling messages for calls routed to the at least one trunk group are routed to the virtual switching point.

33. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 31 wherein the means for routing selected calls so that a common channel signaling control path for the selected calls passes through the network comprises conditioning an ISTP in the common channel signaling control path for the selected calls to release the call in a forward direction and to reconnect the call to a new termination specified by data received from the IVR without releasing the calling party when such data is received at the ISTP.

34. A system for dynamically routing selected calls through an intelligent switched telephone network, comprising:

means for establishing a first termination for the call so that a signaling control path for the call passes through a call control node;

means for releasing the call in a forward direction from the call control node and for reconnecting the call to a new termination specified by data from an external source without releasing a calling party associated with the call.

35. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 34 wherein the means for establishing the first termination for the call comprises:

at least one trunk in at least one trunk group designated for routing the selected calls and an associated routset which routes common channel signaling messages associated with the at least one trunk to the call control node.

36. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 35 wherein the call control node is a virtual node in the switching plane of the network and a physical node in a common channel signaling plane of the network.

37. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 35 wherein the at least one trunk is a loop-back trunk connected to the trunk side of a switching node in the network.

38. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 36 wherein the at least one trunk is a loop-back trunk connected to a trunk side of a switching node in the network.

39. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 37 wherein the at least one trunk is an inter-switch ISUP trunk in the network.

40. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 39 wherein the data network is the Internet.

41. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 39 wherein the data is supplied by a called party at the call termination.

42. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 39 wherein the data is supplied by the calling party which interacts with a machine connected to the data network.

43. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 42 wherein the calling party interacts with the machine through the call connection.

44. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 43 wherein the calling party interacts with the machine using DTMF.

45. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 43 wherein the calling party interacts with the machine using voice commands.

46. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 34 wherein the means for releasing the call in a forward direction from the call control node comprises common channel signaling messages generated by the call control node.

47. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 46 wherein the common channel signaling messages are SS7 ISDN User Part (ISUP) messages.

48. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 34 wherein the call control node is a virtual switching point (VSP) that is assigned a switching node point code.

49. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 34 wherein the call control node is an Intelligent Signaling Transfer Point (ISTP).

50. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 48 wherein the VSP is enabled to perform queries to a Service Control Point (SCP) if a ported number requires translation.

51. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 48 wherein the ISTP is enabled to perform queries to a Service Control Point (SCP) if a ported number requires translation.

52. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 50 wherein the VSP performs queries to the SCP using SS7 Transaction Capabilities Application Part (TCAP) messages.

53. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 51 wherein the ISTP performs queries to the SCP using SS7 Transaction Capabilities Application Part (TCAP) messages.

54. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 50 wherein the VSP uses a data network to perform queries to the SCP.

55. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 51 wherein the ISTP uses a data network to perform queries to the SCP.

56. A system for dynamically routing selected calls through an intelligent switched telephone network as claimed in claim 38 wherein the VSP compiles call records into billing records for billing the selected calls to a service subscriber.