Fault detection and isolation system for an HFC cable network and method therefor

• US 20060218612A1
• Filed: 03/01/2005
• Published: 09/28/2006
• Est. Priority Date: 03/01/2005
• Status: Abandoned Application

• Current Assignee: Time Warner Cable Enterprises LLC (Charter Communications Incorporated)
• Original Assignee: Time Warner Cable Enterprises LLC (Charter Communications Incorporated)
• Inventors: Johnson, Keith, Mandlekar, Amol
• Application Number:
  US11/069,156
• Publication Number:
  US 20060218612A1
• Time in Patent Office: Days
• US Class Current: 725/107
• CPC Class Codes: H04L 43/0817 by checking functioning
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04N 21/2543 Billing , e.g. for subscription services payment schemes, architectures or protocols G06Q20/00; e-commerce G06Q30/00; arrangements for billing for the use of broadcast information or broadcast-related information H04H60/21
• CPC Class Codes: H04N 21/6118 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/6168 involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/6338 directed to network
• CPC Class Codes: H04N 21/6473 Monitoring network processes errors for recovering from a failure of a protocol instance or entity H04L69/40

Abstract

A fault detection and isolation system for an HFC cable network and method therefore. A ping list generator captures set top box (STB) identifying information from a billing system, and STB state information from a network control system. The ping list generator creates a ping list from the STB identifying information and the STB state information, wherein the list comprises the IP address of a set of the addressable STBs connected to an HFC cable network. In an exemplary embodiment, the set is of sufficient size to be representative of the health of the HFC cable network. In another embodiment of the present invention, the set comprises substantially all of the addressable STBs connected to the HFC cable network. A ping generator, pings the IP address of the STB and awaits a response. If the response is received from the STB, then identify the STB as responsive. If the response is not received, then identify the STB as non-responsive. A fault isolation processor associates the STB identifying information and the ping response, determines whether a non-responsive fault indicator is present, and, if the fault indicator is present, then identifies a likely cause of the non-responsive fault.

Claims

1. A fault detection and isolation system for a hybrid fiber coax (HFC) cable network, wherein the HFC cable network comprises a plurality of set top boxes (STBs) and the system comprises:

a ping list generator, wherein the ping list generator is adapted to create a ping list comprising assigned IP addresses of the plurality of addressable set top boxes (STBS) connected to the HFC cable network;

a ping generator, wherein the ping generator is adapted to;

ping an assigned IP address on the ping list and await a response;

if the response is received from the STB, then set an STB operational status as responsive; and

if the response is not received, then set the STB operational status as non-responsive; and

a fault isolation processor is adapted to;

based on the STB operational status, determine whether a fault indicator indicative of a network fault is present; and

if the fault indicator is present, then identify a likely cause of the network fault.

2. The system of claim 1, wherein the ping list generator is further adapted to:

capture set top box (STB) identifying information from a billing system;

capture STB state information from a network control system; and

create the ping list from the STB identifying information and the STB state information.

3. The system of claim 2, wherein STB identifying information is selected from the group consisting of an STB IP address, an STB serial number, an STB manufacturer, an STB MAC address, a node associated with the STB, a modulator associated with the STB and the hub, a demodulator associated with the STB and the hub, a power supply associated with the node, an amplifier associated with the STB, a line extender associated with the STB, a customer account number, a customer account status, a customer address, and a customer phone number.

4. The system of claim 2, wherein the STB state information is selected from the group consisting of an IP address of the STB as determined by a network control system, a node associated with the STB as determined by the network control system, a modulator associated with the STB and the hub as determined by a network control system, a demodulator associated with the STB and the hub as determined by a network control system.

5. The system of claim 1, wherein the plurality of addressable STBs is of sufficient size to be representative of the health of the HFC cable network.

6. The system of claim 1, wherein the plurality of addressable STBs comprises substantially all of the addressable STBs connected to the HFC cable network.

7. The system of claim 1, wherein the ping generator further comprises a parent ping script adapted to:

create a sublist from the ping list, wherein the sublist comprises assigned IP addresses of a subset of the plurality of addressable STBs connected to the HFC cable network;

assign the sublist to a child script, wherein the child script is adapted to ping the STB IP addresses on the sublst and wait for responses;

collect responses; and

provide the child script another sublist.

8. The system of claim 1, wherein the fault isolation processor is further adapted to:

associate the STB operational status with a node;

associate the node with a demodulator; and

associate the demodulator with a hub.

9. The system of claim 8, wherein the fault isolation processor is further adapted to:

establish a node minimum responsiveness measure expressed as ratio of STBs associated with the node that responded to the ping to the total number of STBs associated with the node that were pinged; and

wherein the fault indicator comprises a failure of the node to meet or exceed the node minimum responsive measure.

10. The system of claim 8, wherein the fault isolation processor is further adapted to:

establish a demodulator minimum responsiveness measure expressed as ratio of STBs associated with the demodulator that responded to the ping to the total number of STBs associated with demodulator that were pinged;

and wherein the fault indicator comprises a failure of the demodulator to meet or exceed the demodulator minimum responsive measure.

11. The system of claim 8, wherein the fault isolation processor is further adapted to:

establish a hub minimum responsiveness measure expressed as ratio of STBs associated with the hub that responded to the ping to the total number of STBs associated with hub that were pinged;

and wherein the fault indicator comprises a failure of the hub to meet or exceed the hub minimum responsive measure.

12. The system of claim 9, wherein the demodulator is associated with a first and second node, and the fault isolation processor is further adapted to:

determine whether the first node meets or exceeds the node minimum responsiveness measure;

if the first node does not meet or exceed the node minimum responsiveness measure, then determine whether a second node meets or exceeds the node minimum responsiveness measure;

if the second node meets or exceeds the node minimum responsiveness measure, then identify the likely cause of the network fault as a failure of the first node; and

if the second node does not meet or exceed the minimum responsiveness measure, then identify the likely cause of the network fault as a failure of the demodulator.

13. The system of claim 10, wherein the hub is associated with a first and second demodulator, and the fault isolation processor is further adapted to:

determine whether the first demodulator meets or exceeds the demodulator minimum responsiveness measure;

if the first demodulator does not meet or exceed the demodulator minimum responsiveness measure, then determine whether the second demodulator meets or exceeds the demodulator minimum responsiveness measure;

if the second demodulator meets or exceeds the demodulator minimum responsiveness measure, then identify the likely cause of the network fault as a failure of a network segment emanating downstream from the first demodulator; and

if the second demodulator does not meet or exceed the demodulator minimum responsiveness measure, then identify the likely cause of the network fault as a failure of the hub.

14. The system of claim 1, wherein the STB further comprises manufacturer identifying information associating the STB with a manufacturer, and wherein the fault isolation processor is further adapted to, if the fault indicator is present, determine whether the likely cause of the network fault is the STBs of the manufacturer based on the operational status of the STBs of the manufacturer.

15. The system of claim 14, wherein the manufacturer identifying information comprises a manufacturer'"'"'s name.

16. The system of claim 15, wherein the manufacturer identifying information further comprises an STB model number.

17. The system of claim 16, wherein the manufacturer identifying information further comprises an STB release number.

18. The system of claim 8 further comprising a polling generator adapted to:

poll a responsive STB for a reverse data carrier (RDC) level;

store the RDC level in a polling data file; and

wherein the fault isolation processor is further adapted to;

establish an RDC responsiveness measure expressed as an maximum average of the RDC level of each STB associated with the hub;

determine whether the RDC responsiveness measure has been exceeded; and

if the RDC responsiveness measure has been exceeded, then evaluate network segments upstream from the STBs for network faults.

19. The system of claim 18, further comprising:

wherein the polling data file further comprises a manufacturer of the STB and wherein the fault isolation processor is further adapted to;

determine an average RDC level of STBs of each manufacturer associated with the hub;

determine whether the average RDC level of STBs of a manufacturer exceed the RDC responsiveness measure; and

if the average RDC level of STBs of the manufacturer exceeds the RDC responsiveness measure, then take remedial action with respect to the STBs of the manufacturer.

20. A method of detecting a fault in a hybrid fiber coax (HFC) cable network wherein the HFC cable network comprises a plurality of addressable set top boxes (STBs) and the method comprises:

creating a ping list comprising an assigned IP addresses of the plurality of addressable set top boxes (STBs) connected to the HFC cable network;

pinging an assigned IP address on the ping list and awaiting a response;

if the response is received from the STB, then setting an STB operational status as responsive; and

if the response is not received, then setting the STB operational status as non-responsive;

determining whether a fault indicator indicative of a network fault is present; and

if the fault indicator is present, then identifying a likely cause of the network fault and taking remedial action to correct the likely cause.

21. The method of detecting a fault in an HFC cable network of claim 20, wherein creating a ping list comprises:

capturing set top box (STB) identifying information from a billing system;

capturing STB state information from a network control system; and

creating the ping list from the STB identifying information and the STB state information.

22. The method of detecting a fault in an HFC cable network of claim 21, wherein STB identifying information is selected from the group consisting of an STB IP address, an STB serial number, an STB manufacturer, an STB MAC address, a node associated with the STB, a modulator associated with the STB and the hub, a demodulator associated with the STB and the hub, a power supply associated with the node, an amplifier associated with the STB, a line extender associated with the STB, a customer account number, a customer account status, a customer address, and a customer phone number.

23. The method of detecting a fault in an HFC cable network of claim 21, wherein the STB state information is selected from the group consisting of an IP address of the STB as determined by a network control system, a node associated with the STB as determined by the network control system, a modulator associated with the STB and the hub as determined by a network control system, a demodulator associated with the STB and the hub as determined by a network control system.

24. The method of detecting a fault in an HFC cable network of claim 20, wherein the plurality of addressable STBs is of sufficient size to be representative of the health of the HFC cable network.

25. The method of detecting a fault in an HFC cable network of claim 20, wherein the plurality of addressable STBs comprises substantially all of the addressable STBs connected to the HFC cable network.

26. The method of detecting a fault in an HFC cable network of claim 20, wherein the method further comprises:

creating a sublist from the ping list, wherein the sublist comprises a subset of a set of STB IP addresses on the ping list;

assigning the sublist to a child script, wherein the child script is adapted to ping the STB IP addresses on the sublist and wait for responses;

collecting responses; and

providing the child script another sublist.

27. The method of detecting a fault in an HFC cable network of claim 20, further comprising:

associating the STB operational status with a node;

associating the node with a demodulator; and

associating the demodulator with a hub.

28. The method of detecting a fault in an HFC cable network of claim 27 further comprising establishing a node minimum responsiveness measure expressed as ratio of STBs associated with the node that responded to the ping to the total number of STBs associated with the node that were pinged;

and wherein determining whether the fault indicator indicative of a network fault is present comprises determining whether the node meets or exceeds the node minimum responsive measure.

29. The method of detecting a fault in an HFC cable network of claim 27 further comprising establishing a demodulator minimum responsiveness measure expressed as ratio of STBs associated with the demodulator that responded to the ping to the total number of STBs associated with demodulator that were pinged;

and wherein determining whether the fault indicator indicative of a network fault is present comprises determining whether the demodulator meets or exceeds the demodulator minimum responsive measure.

30. The method of detecting a fault in an HFC cable network of claim 27 further comprising establishing a hub minimum responsiveness measure expressed as ratio of STBs associated with the hub that responded to the ping to the total number of STBs associated with hub that were pinged, and wherein determining whether the fault indicator indicative of a network fault is present comprises determining whether the hub meets or exceeds the hub minimum responsive measure.

31. The method of detecting a fault in an HFC cable network of claim 28, wherein a demodulator is associated with a first and second node, and the method further comprises:

determining whether the first node meets or exceeds the node minimum responsiveness measure;

if the first node does not meet or exceed the node minimum responsiveness measure, then determining whether a second node meets or exceeds the node minimum responsiveness measure;

if the second node meets or exceeds the node minimum responsiveness measure, then identifying the likely cause of the network fault as a failure of the first node; and

if the second node does not meet or exceed the minimum responsiveness measure, then identifying the likely cause of the network fault as a failure of the demodulator.

32. The method of detecting a fault in an HFC cable network of claim 29, wherein a hub is associated with a first and second demodulator, and the method further comprises:

determining whether the first demodulation meets or exceeds the demodulator minimum responsiveness measure;

if the first demodulator does not meet or exceed the demodulator minimum responsiveness, then determining whether the second demodulator meets or exceeds the demodulator minimum responsiveness measure;

if the second demodulator meets or exceeds the demodulator minimum responsiveness measure, then identifying the likely cause of the network fault as a failure of a network segment emanating downstream from the first demodulator; and

if the second demodulator does not meet or exceed the demodulator minimum responsiveness measure, then identifying the likely cause of the network fault as a failure of the hub.