Method and system for processing telephone calls via a remote tie-line

• US 7,274,786 B2
• Filed: 03/24/2003
• Issued: 09/25/2007
• Est. Priority Date: 01/17/2001
• Status: Expired due to Fees

• Current Assignee: AT&T Labs Incorporated (AT&T, Inc.)
• Original Assignee: AT&T Labs Incorporated (AT&T, Inc.)
• Inventors: Stroud, Kenneth Robert, Fleischer, Harold C. III, Simino, John E.
• Primary Examiner(s): Hong; Harry S.
• Application Number:
  US10/393,938
• Publication Number:
  US 20030235284A1
• Time in Patent Office: 1,646 Days
• Field of Search: 379/219, 379/220.01, 379/221.01, 379/221.02, 379/221.03, 379/221.08, 379/221.09, 379/221.12, 379/221.14, 379/224, 379/225, 379/230, 379/231, 379/232, 379/234, 379/901
• US Class Current: 379/221.03
• CPC Class Codes: H04M 2207/35 virtual private networks
• CPC Class Codes: H04M 7/009 in systems involving PBX or KTS networks
• CPC Class Codes: H04M 7/0096 Trunk circuits
• CPC Class Codes: H04M 7/12 for working between exchanges having different types of switching equipment, e.g. power-driven and step by step or decimal and non-decimal
• CPC Class Codes: H04Q 2213/13091 CLI, identification of calling line
• CPC Class Codes: H04Q 2213/1313 Metering, billing
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13176 Common channel signaling, CCS7
• CPC Class Codes: H04Q 2213/13196 Connection circuit/link/trunk/junction, bridge, router, gateway
• CPC Class Codes: H04Q 2213/1322 PBX
• CPC Class Codes: H04Q 2213/13222 PBX circuits in public exchange, centrex
• CPC Class Codes: H04Q 2213/13224 Off-net subscriber, dial in to/out from network, teleworking
• CPC Class Codes: H04Q 2213/1329 Asynchronous transfer mode, ATM
• CPC Class Codes: H04Q 2213/13345 Intelligent networks, SCP
• CPC Class Codes: H04Q 2213/13383 Hierarchy of switches, main and subexchange, e.g. satellite exchange
• CPC Class Codes: H04Q 2213/13384 Inter-PBX traffic, PBX networks, e.g. corporate networks
• CPC Class Codes: H04Q 2213/13395 Permanent channel, leased line
• CPC Class Codes: H04Q 2213/13399 Virtual channel/circuits
• CPC Class Codes: H04Q 3/62 for connecting to private branch exchanges
• CPC Class Codes: H04Q 3/66 Traffic distributors
• CPC Class Codes: H04Q 3/76 : Translation from the called subscriber's number to the outgoing or incoming control information
• CPC Class Codes: Y10S 379/901 : Virtual networks or virtual private networks

Abstract

A method and system include routing telephone calls from multiple private networks via public lines and trunks in a public switched telephone network (PSTN) to a host switch, at which the connections would begin to run parallel. The host switch routes the telephone calls via a private trunk group to a private facility, such as an electronic tandem network (ETN) node or an asynchronous transfer mode (ATM) switch. If the private trunk group is full or unavailable, the host switch routes the telephone calls over alternate private or public trunk groups and selected carriers.

Claims

1. A method for routing a call to a called party number, comprising:

routing the call, via at least one public trunk group, to a switch hosting an automatic selection of facilities-remote tie-line (ASF-RTL) number; and

routing the call, via a private trunk group, from the switch hosting the ASF-RTL number to a switch hosting the called party number.

2. The method for routing the call according to claim 1, further comprising:

routing the call from the switch hosting the ASF-RTL number to the switch hosting the called party number via an alternate public trunk group when the private trunk group is determined to be not available.

3. The method for routing the call according to claim 2, further comprising:

determining a carrier associated with the alternate public trunk group; and

routing the call from the switch hosting the ASF-RTL number to the switch hosting the called party number via the alternate public trunk group using the determined carrier.

4. The method for routing the call according to claim 2, in which the private trunk group is determined to be not available when the private trunk group is busy.

5. The method for routing the call according to claim 1, further comprising:

routing the call from the switch hosting the called party number to an international gateway when the called party number comprises an international number.

6. The method for routing the call according to claim 5, in which routing the call to the international gateway comprises routing the call via a second private trunk group.

7. The method for routing the call according to claim 1, in which the ASF-RTL number is associated with a private network that includes the called party number.

8. The method for routing the call according to claim 7, in which the private network comprises at least one of a central exchange (Centrex) and a private branch exchange (PBX).

9. The method for routing the call according to claim 1, in which the switch hosting the called party number comprises one of an electronic tandem network node and an asynchronous transfer mode switch.

10. A method for routing a call to a called party number, though a private network and a public switched telephone network (PSTN), the method comprising:

changing a called party identifier from a first number, corresponding to the called party number, to a second number, corresponding to a private trunk group associated with the private network;

routing the call to a switch hosting the private trunk group based on the called party identifier;

changing the called party identifier back to the first number; and

routing the call from the host switch to the called party number, via at least the private trunk group, based on the called party identifier.

11. The method for routing the call according to claim 10, further comprising:

setting a redirecting number to the first number when the called party identifier is changed from the first number to the second number, wherein the called party identifier is changed back to the first number by referencing the redirecting number.

12. The method for routing the call according to claim 10, further comprising:

determining an alternative trunk group by which to route the call; and

routing the call from the host switch to the called party number, via at least the alternative trunk group, based on the called party identifier, when the private trunk group is not available.

13. The method for routing the call according to claim 12, further comprising:

determining a carrier associated with the alternative trunk group when the alternative trunk group comprises a public trunk group.

14. The method for routing the call according to claim 10, further comprising:

determining whether the call to is subject to routing via the private trunk group based on at least one of the called party number, a calling party number, a type of call, a date, a day of week, a time of day and a percentage allocation.

15. The method for routing the call according to claim 10, in which the second number comprises an automatic selection of facilities-remote tie-line (ASF-RTL) telephone number.

16. An apparatus for routing a call to a called party number through at least one private trunk group associated with an automatic selection of facilities-remote tie-line (ASF-RTL) number, the system comprising:

a service control point in a public switched telephone network (PSTN) that instructs an originating switch to route the call to a switch hosting the ASF-RTL number, and that instructs the host switch to route the call to a terminating switch associated with the called party number via the at least one private trunk group.

17. The apparatus for routing the call according to claim 16, in which the service control initially determines whether the call is subject to routing through the at least one private trunk group based on at least the called party number.

18. The apparatus for routing the call according to claim 17, in which the service control point further determines whether the called party number comprises an international number, and if so, instructs the terminating switch to route the call to an international gateway via a second private trunk group.

19. The apparatus for routing the call according to claim 17, in which the service control point further determines whether the called party number comprises a long distance number, and if so, instructs the terminating switch to route the call to an interexchange carrier switch via a second private trunk group.

20. The apparatus for routing the call according to claim 16, in which the called party number is associated with one a central exchange (Centrex) and a private branch exchange (PBX).

21. The apparatus for routing the call according to claim 16, in which the terminating switch comprises one of an electronic tandem network node and an asynchronous transfer mode switch.

22. The apparatus for routing the call according to claim 16, in which the at least one private trunk group comprises a multi-frequency trunk.

23. A system for routing calls through a public telecommunications network, comprising:

a plurality of trunk groups, comprising at least one private trunk group and at least one public trunk group, the at least one private trunk group having an associated number and host switch; and

a processor in the public telecommunications network that identifies each call entitled to use the at least one private trunk group, based on at least a called party number, and that changes a called party identifier of each entitled call from indicating the respective called party number to indicating the private trunk group number;

wherein each entitled call is routed to the host switch, via the at least one public trunk group, based on the called party identifier, the host switch routing the call through the at least one private trunk group to a terminating switch associated with the respective called party number.