Next-generation network that reduces the effect of a service failure

• US 20060072732A1
• Filed: 10/14/2003
• Published: 04/06/2006
• Est. Priority Date: 10/14/2003
• Status: Active Grant

• Current Assignee: Tellabs Petaluma, Inc. (Infinera Corp.)
• Original Assignee: Tellabs Petaluma, Inc. (Infinera Corp.)
• Inventors: Varble, T. Bryan, Bivin, Robert A.
• Granted Patent: US 7,218,723 B2
• Time in Patent Office: Days
• US Class Current: 379/211.10
• CPC Class Codes: H04M 7/0066 Details of access arrangements to the networks where the access arrangement is a PSTN/ISDN access H04M7/122

Abstract

A next-generation network utilizes a three-tier, cascading fault approach to providing emergency stand-alone (ESA) switching in a circuit-to-packet (C2P) network. Calls that are placed to destination numbers which are connected to the same local network device are completed even when connectivity with a community network level has been interrupted, while calls that are placed to destination numbers which are connected to the same community are completed even when connectivity with a gateway media controller has been interrupted.

Claims

1. A network comprising a plurality of termination service area (TSA) devices, each TSA device being connectable to a plurality of customer devices, a public switched-telephone network (PTSN), and a data network, a TSA device having a database, a state machine connected to the database, and local calling circuitry connected to the state machine, when a communications link fails, the state machine:

establishes an end-to-end voice connection between a first customer device and a second customer device when both the first and the second customer devices are connected to a same TSA device; and

returns an indication that a connection can not be made at this time to a customer device that requested a connection when the first and second customer devices are not connected to the same TSA device.

2. The network of claim 1 wherein the TSA device determines a link status, and

when the link status is negative, the state machine looks up a dialed number in a device database to determine if the dialed number is in the database;

when the dialed number is in the device database, the state machine directs the local calling circuitry to make the end-to-end connection between the first user device and the second user device; and

when the dialed number is not in the device database, returning the indication to the first user device that a connection can not be made at this time.

3. The network of claim 2 wherein when the link status is positive, the TSA device determines whether forwarding information has been received from a media gateway controller.

4. The network of claim 3 wherein the TSA device:

detects an off-hook condition from the first user device;

when the off-hook condition is detected, determines a dialed number that identifies the second user device; and

when the dialed number has been determined, forwards the dialed number to the media gateway controller.

5. The network of claim 4 wherein the TSA device:

determines if forwarding information for the dialed number has been received;

when forwarding information has been received, outputs a call by either switching the call onto the PSTN or packetizing and routing the call over a data network; and

when the forwarding information has not yet been received, determining the link status.

6. The network of claim 1 and further comprising a plurality of community service area (CSA) media gateways, each CSA media gateway being connected to a number of TSA devices, a CSA media gateway having a CSA database, a CSA state machine connected to the CSA database, and community calling circuitry connected to the CSA state machine.

7. The network of claim 6 wherein when a communications link fails, the CSA state machine:

establishes an end-to-end voice connection between the first customer device and the second customer device when the first customer device is connected to the CSA media gateway via a first TSA device, and the second customer is connected to the CSA media gateway via the first TSA device or a second TSA device; and

returns an indication that a connection can not be made at this time to a customer device that requested a connection when the first and second customer devices are not connected to TSA devices that are connected to a same CSA media gateway.

8. The network of claim 7 and further comprising a media gateway controller connected to a number of CSA media gateways, the media gateway controller controlling connections between a large number of customer devices, including the first customer device and the second customer device.

9. A method of operating a network device, the method comprising the steps of:

determining a link status;

when the link status is negative, looking up a dialed number in a device database to determine if the dialed number is in the device database;

when the dialed number is in the device database, making an end-to-end connection between a first user device and a second user device; and

when the dialed number is not in the device database, returning an indication to the first user device that a connection can not be made at this time.

10. The method of claim 9 wherein:

a local device is connected to a plurality of customers with a plurality of telephone numbers; and

911 calls are routed to a predefined set of telephone numbers that are connected to a same local device as an originating caller.

11. The method of claim 9 wherein when the link status is positive, determining whether forwarding information has been received from a media gateway controller.

12. The method of claim 9 and further comprising the steps of:

detecting an off-hook condition from the first user device;

when an off-hook condition is detected, determining a dialed number that identifies a second user device; and

when the dialed number has been determined, forwarding the dialed number to the media gateway controller.

13. The method of claim 12 and further comprising the step of determining if forwarding information for the dialed number has been received.

14. The method of claim 13 wherein:

when forwarding information has been received, outputting a call by either switching the call onto the PSTN or packetizing and routing the call over a data network; and

when the forwarding information has not yet been received, determining the link status.

15. The method of claim 9 wherein the network device is connected to a plurality of customer devices and a concentrating network device that is connected to a plurality of network devices.

16. The method of claim 9 wherein the network device is connected to a media gateway controller and a plurality of local devices that are connected to a plurality of customer devices.