Early warning fault identification and isolation system for a two-way cable network

• US 20060218609A1
• Filed: 03/01/2005
• Published: 09/28/2006
• Est. Priority Date: 03/01/2005
• Status: Active Grant

• Current Assignee: Time Warner Cable Enterprises LLC (Charter Communications Incorporated)
• Original Assignee: Time Warner Cable Inc. (Charter Communications Incorporated)
• Inventors: Johnson, Keith, Mandlekar, Amol
• Granted Patent: US 7,594,252 B2
• Time in Patent Office: Days
• US Class Current: 725/105
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/0817 by checking functioning
• 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 21/64322 IP
• CPC Class Codes: H04N 21/6473 Monitoring network processes errors for recovering from a failure of a protocol instance or entity H04L69/40

Abstract

Set top boxes (STBs) connected to the HFC cable network are “pinged” and their responses recorded. The two most responsive STBs in each node of the HFC cable network are identified. The most responsive STB is added to a primary ping list and the next most responsive STB is added to a secondary ping list. The STBs on the primary list are “pinged” and their responses recorded. If an STB on the primary list fails to respond, the secondary STB associated with the node is pinged. If both the primary and secondary STB associated with a node fail to respond to the “ping,” the node is identified as non-responsive. If all of the nodes associated with a modulator (or a demodulator) are identified as non-responsive, the modulator (or demodulator) is identified as “non-responsive.” Additionally, network devices are pinged and their responses noted. Using the responsiveness of nodes and network devices, faults in segments in an HFC cable network can be identified and located.

Claims

1. A method of determining an operational status of a segment of a hybrid fiber coax (HFC) cable network comprising:

selecting a primary set top box (STB) and a secondary STB, wherein the primary STB and the secondary STB are connected to the HFC cable network and are associated with a node of the HFC cable network, and wherein the primary STB is associated with a primary STB IP address and the secondary STB is associated with a secondary STB IP address;

pinging the primary STB IP address;

determining whether a response is received from the primary STB;

if a response is received from the primary STB, then setting a primary STB operational status of the primary STB to responsive;

if a response is not received from the primary STB, pinging the secondary STB IP address;

determining whether a response is received from the secondary STB;

if a response is received from the secondary STB, then setting a secondary STB operational status of the secondary STB to responsive and setting the node operational status of the node to responsive;

if a response is not received from the secondary STB, then setting the secondary STB operational status of the secondary STB to non-responsive and setting the node operational status of the node to non-responsive; and

determining an operational status of a network segment upstream from the node based on the node operational status of all nodes serviced by the network segment upstream from the node.

2. The method of determining an operational status of a segment of an HFC cable network of claim 1, wherein the HFC cable network comprises a set of STBs and wherein selecting the primary STB and the secondary STB comprises:

pinging an IP addresses associated with the set of STBs periodically;

for each pinged STB of the set of STBs, recording whether the pinged STB responded to the ping over a predetermined number of ping periods;

for each pinged STB of the set of STBs, determining a ratio of ping attempts to responses over the predetermined number of ping periods;

selecting a first pinged STB of the set of STBs with the highest ratio of ping attempts to responses as the primary STB; and

selecting a second pinged STB of the set of STBs with the next highest ratio of ping attempts to responses as the secondary STB.

3. The method of determining an operational status of a segment of an HFC cable network of claim 1, wherein the method further comprises:

creating a node display string comprising data elements indicative of the node operational status;

sending the node display string to a display server; and

displaying the data elements indicative of the node operational status.

4. The method of determining an operational status of a segment of an HFC cable network of claim 1, wherein the upstream component comprises a demodulator and wherein determining the operational status of a component upstream from the node based on the node operational status of all nodes serviced by the upstream component comprises:

determining the node operational status of nodes associated with the demodulator;

if the node operational status of at least one node associated with the demodulator is responsive, then setting a demodulator operational status of the demodulator to responsive; and

if the node operational status of the nodes associated with the demodulator is non-responsive, then setting the demodulator operational status of the demodulator to non-responsive; and

taking remedial action to repair the demodulator.

5. The method of determining an operational status of a segment of an HFC cable network of claim 4, wherein the method further comprises:

creating a demodulator display string comprising data elements indicative of the demodulator operational status;

sending the demodulator display string to a display server; and

displaying the data elements indicative of the demodulator operational status.

6. The method of determining an operational status of a segment of an HFC cable network of claim 5, wherein the upstream component comprises a modulator and wherein determining the operational status of a component upstream from the node based on the node operational status of all nodes serviced by the upstream component comprises:

determining the node operational status of nodes associated with the modulator;

if the node operational status of at least one node associated with the modulator is responsive, then setting a modulator operational status of the modulator to responsive;

if the node operational status of the nodes associated with the modulator is non-responsive, then setting the modulator operational status of the modulator to non-responsive; and

taking remedial action to repair the modulator.

7. The method of determining an operational status of a segment of an HFC cable network of claim 6, wherein the method further comprises:

creating a modulator display string comprising data elements indicative of the modulator operational status;

sending the modulator display string to a display server; and

displaying the data elements indicative of the modulator operational status.

8. The method of determining an operational status of a segment of an HFC cable network of claim 1, wherein the method further comprises:

obtaining an IP address of a network component associated with the node;

pinging the network component IP address;

determining whether a response is received from the network component;

if a response is received from the network component, then setting a component operational status of the network component to responsive;

if a response is not received from the network component, then setting the component operational status of the network component to non-responsive; and

taking remedial action to repair the network component.

9. The method of determining an operational status of a segment of an HFC cable network of claim 8, wherein the network component is selected from group consisting of an edge device, a router, and a switch.

10. The method of determining an operational status of a segment of an HFC cable network of claim 8, wherein the method further comprises:

creating a network component display string comprising data elements indicative of the component operational status;

sending the network component display string to a display server; and

displaying the data elements indicative of the component operational status.

11. The method of determining an operational status of a segment of an HFC cable network of claim 8, wherein the method further comprises determining an operational status of a component downstream from the node based on the component operational status of network components downstream from the node.

12. A system for determining an operational status of a segment of a hybrid fiber coax (HFC) cable network comprising:

a ping list generator, wherein the ping list generator is adapted to select a primary set top box (STB) and a secondary STB for pinging, wherein the primary STB and the secondary STB are connected to the HFC cable network and are associated with a node of the HFC cable network, and wherein the primary STB is associated with a primary STB IP address and the secondary STB is associated with a secondary STB IP address;

a STB pinger adapted to;

receive a ping list from the ping list generator comprising IP addresses associated with STBs;

ping the IP address of each STB on the ping list;

if a response is received from an STB associated with a pinged IP address, set an STB operational status of the STB as responsive; and

if a response is not received from the STB associated with the pinged IP address, set the STB operational status of the STB as non-responsive; and

a results processor adapted to;

determine an STB operational status of the primary STB;

if the primary STB operational status is responsive, then set a node operational status to responsive;

if the primary STB operational status is non-responsive, then send the secondary IP address to the STB pinger;

determine an STB operational status of the secondary STB; and

if the secondary STB operational status is non-responsive, then set the node operational status to nonresponsive; and

a final results processor adapted to determine an operational status of a network segment upstream from the node based on the node operational status of all nodes serviced by the network segment upstream from the node.

13. The system of claim 12, wherein the HFC cable network comprises a set of STBs and the ping list generator is further adapted to:

ping IP addresses associated with the set of STBs periodically;

for each pinged STB of the set of STBs, record whether the pinged STB responded to the ping over a fix number of ping periods;

for each pinged STB of the set of STBs, determine a ratio of ping attempts to responses;

select a first pinged STB of the set of STBs with the highest ratio of ping attempts to responses as the primary STB; and

select a second pinged STB of the set of STBs with the next highest ratio of ping attempts to responses as the secondary STB.

14. The system of claim 12 wherein the final results processor is further adapted to:

create a node display string comprising data elements indicative of the node operational status; and

send the node display string to a display server; and

wherein the display server is adapted to display the data elements indicative of the node operational status.

15. The system of claim 12, wherein the upstream component comprises a demodulator and wherein the final results processor is further adapted to:

determine the node operational status of nodes associated with the demodulator;

if the node operational status of at least one node associated with the demodulator is responsive, then set a demodulator operational status of the demodulator to responsive; and

if the node operational status of the nodes associated with the demodulator is non-responsive, then set the demodulator operational status of the demodulator to non-responsive.

16. The system of claim 15 wherein the final results processor is further adapted to:

create a demodulator display string comprising data elements indicative of the demodulator operational status; and

send the demodulator display string to a display server; and

wherein the display server is adapted to display the data elements indicative of the demodulator operational status.

17. The system of claim 12, wherein the upstream component comprises a modulator and wherein the final results processor is further adapted to:

determine the node operational status of nodes associated with the modulator;

if the node operational status of at least one node associated with the modulator is responsive, then set the modulator operational status of the modulator to responsive; and

if the node operational status of the nodes associated with the modulator is non-responsive, then set the modulator operational status of the modulator to non-responsive.

18. The system of claim 17 wherein the final results processor is further adapted to:

create a modulator display string comprising data elements indicative of the modulator operational status; and

send the modulator display string to a display server; and

wherein the display server is adapted to display the data elements indicative of the modulator operational status.

19. The system of claim 12, wherein the system further comprises a network component pinger adapted to:

obtain an IP address of a network component associated with the node;

ping the network component IP address;

determine whether a response is received from the network component;

if a response is received from the network component, then set a component operational status of the network component to responsive; and

if a response is not received from the network component, then set the component operational status of the network component to non-responsive.

20. The system of claim 19, wherein the network component is selected from group consisting of an edge device, a router, and a switch.

21. The system of claim 19 wherein the final results processor is further adapted to:

create a network component display string comprising data elements indicative of the component operational status; and

send the network component display string to a display server; and

wherein the display server is adapted to display the data elements indicative of the component operational status.

22. The system of claim 19, wherein the final results processor is further adapted to determine an operational status of a component downstream from the node based on the component operational status of network components downstream from the node.