Early Warning Fault Identification and Isolation System for a Two-Way Cable Network

• US 20090300702A1
• Filed: 08/04/2009
• Published: 12/03/2009
• 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, Mandelkar, Amol
• Granted Patent: US 7,930,725 B2
• Time in Patent Office: Days
• US Class Current: 725/129
• 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

A system and method for determining an operational status of a segment of a hybrid fiber coax (HFC) cable network. Subscriber premises units (SPUs) connected to the HFC cable network are “pinged” and their responses recorded. The two most responsive SPUs in each node of the HFC cable network are identified. The most responsive SPU is added to a primary ping list and the next most responsive SPU is added to a secondary ping list. The SPUs on the primary list are “pinged” and their responses recorded. If an SPU on the primary list fails to respond, the secondary SPU associated with the node is pinged. If both the primary and secondary SPU 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:

accessing a ping datastore to acquire ping data associated with a plurality of subscriber premises units (SPUs) connected to the HFC network through a common node, wherein the ping data comprise for each SPU of the plurality of SPUs a ratio of a number of ping responses to a number of ping queries;

selecting from the ping data associated with the plurality of SPUs a primary SPU, wherein the primary SPU has the highest ratio of ping responses to ping queries and wherein the primary SPU is associated with a primary SPU IP address; and

selecting from the ping data associated with the plurality of SPUs a secondary SPU, wherein the secondary SPU has the second highest ratio of ping responses to ping queries and wherein the secondary SPU is associated with a secondary SPU IP address;

pinging the primary SPU IP address;

determining whether a response from the ping is received from the primary SPU;

when a response from the ping is received from the primary SPU, then setting a primary SPU operational status of the primary SPU to responsive;

when a response from the ping is not received from the primary SPU, pinging the secondary SPU IP address;

determining whether a response from the ping is received from the secondary SPU;

when a response from the ping is received from the secondary SPU, then setting a secondary SPU operational status of the secondary SPU to responsive and setting a node operational status of the common node to responsive;

when a response from the ping is not received from the secondary SPU, then setting the secondary SPU operational status of the secondary SPU to non-responsive and setting the node operational status of the common node to non-responsive; and

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

2. The method of claim 1 further comprising:

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

sending the node display string to a display server; and

displaying the data elements indicative of the node operational status of the common node.

3. The method of claim 1, wherein the plurality of SPUs are set top boxes (STBs) and wherein the STBs are addressable via an out-of-band channel (OOBC), wherein the upstream network component comprises an OOBC demodulator and wherein determining the operational status of a network component upstream from the common node based on the node operational status of all nodes serviced by the upstream network component comprises:

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

when the node operational status of at least one node associated with the OOBC demodulator is responsive, then setting an OOBC demodulator operational status of the OOBC demodulator to responsive; and

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

taking remedial action to repair the OOBC demodulator.

4. The method of claim 3 further comprising:

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

sending the OOBC demodulator display string to a display server; and

displaying the data elements indicative of the OOBC demodulator operational status.

5. The method of claim 1, wherein the plurality of SPUs are set top boxes (STBs) and wherein the STBs are addressable via an out-of-band channel (OOBC), wherein the upstream network component comprises an OOBC modulator and wherein determining the operational status of a network component upstream from the common node based on the node operational status of all nodes serviced by the upstream network component comprises:

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

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

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

taking remedial action to repair the OOBC modulator.

6. The method of claim 5 further comprising:

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

sending the OOBC modulator display string to a display server; and

displaying the data elements indicative of the OOBC modulator operational status.

7. The method of claim 1, wherein the plurality of SPUs are cable modems (CMs) and wherein the CMs are addressable via a high speed data channel (HSDC), wherein the upstream network component comprises an HSDC modulator and wherein determining the operational status of a network component upstream from the common node based on the node operational status of all nodes serviced by the upstream network component comprises:

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

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

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

taking remedial action to repair the HSDC modulator.

8. The method of claim 7 further comprising:

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

sending the HSDC modulator display string to a display server; and

displaying the data elements indicative of the HSDC modulator operational status.

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

a plurality of nodes;

a ping list generator, wherein for each node of the plurality of nodes the ping list generator is configured for;

accessing a ping datastore to acquire ping data associated with a plurality of subscriber premises units (SPUs) connected to the HFC network through a common node, wherein the ping data comprise for each SPU of the plurality of SPUs a ratio of a number of ping responses to a number of ping queries;

selecting from the ping data associated with the plurality of SPUs a primary SPU, wherein the primary SPU has the highest ratio of ping responses to ping queries and wherein the primary SPU is associated with a primary SPU IP address;

adding the primary SPU IP address to a primary SPU ping list;

selecting from the ping data associated with the plurality of SPUs a secondary SPU, wherein the secondary SPU has the second highest ratio of ping responses to ping queries and wherein the secondary SPU is associated with a secondary SPU IP address; and

adding the secondary SPU IP address to a secondary SPU ping list;

an SPU pinger, wherein the SPU pinger is configured for;

receiving from the ping list generator the primary SPU ping list and the secondary SPU ping list;

pinging the primary IP address of each primary SPU on the primary SPU ping list;

setting an SPU operational status of the primary SPU as responsive when a response from the ping is received; and

setting the SPU operational status of the primary SPU as non-responsive when the response from the ping is not received;

pinging a secondary IP address of a secondary SPU on the secondary SPU ping list when instructed by a results processor;

setting an SPU operational status of the secondary SPU as responsive when the response from the ping is received; and

setting the SPU operational status of the secondary SPU as non-responsive when the response from the ping is not received;

the results processor, wherein the results processor is configured for;

determining an SPU operational status of the primary SPU;

setting a node operational status of the common node associated with the pinged SPU to responsive when the primary SPU operational status is responsive;

instructing the SPU pinger to ping the secondary IP address of the secondary SPU associated with the common node and to set an operation status of the secondary SPU when the primary SPU operational status of the primary SPU associated with the common node is non-responsive;

determining an SPU operational status of the secondary SPU;

setting the node operational status to responsive when the secondary SPU operation status is responsive; and

setting the node operational status to non-responsive when the secondary SPU operational status is non-responsive; and

a final results processor, wherein the final results processor is configured for determining an operational status of a network component upstream from the common node based on the node operational status of all nodes serviced by the upstream network component.

10. The system of claim 9, wherein the final results processor is further configured for:

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

sending the node display string to a display server; and

wherein the display server is configured for displaying the data elements indicative of the common node operational status.

11. The system of claim 9, wherein the plurality of SPUs are set top boxes (STBs) and wherein the STBs are addressable via an out-of-band channel (OOBC), wherein the upstream network component comprises an OOBC demodulator and wherein the final results processor is further configured for:

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

setting a OOBC demodulator operational status of the demodulator to responsive when the node operational status of at least one node associated with the OOBC demodulator is responsive; and

setting the OOBC demodulator operational status of the demodulator to non-responsive when the node operational status of the nodes associated with the OOBC demodulator is non-responsive.

12. The system of claim 11, wherein the final results processor is further configured for:

creating an OOBC demodulator display string comprising data elements indicative of the OOBC demodulator operational status; and

sending the OOBC demodulator display string to a display server; and

wherein the display server comprises instruction for displaying the data elements indicative of the OOBC demodulator operational status.

13. The system of claim 9, wherein the plurality of SPUs are set top boxes (STBs) and wherein the STBs are addressable via an out-of-band channel (OOBC), wherein the upstream network component comprises an OOBC modulator and wherein the final results processor is further configured for:

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

setting the OOBC modulator operational status of the OOBC modulator to responsive when the node operational status of at least one node associated with the OOBC modulator is responsive; and

setting the OOBC modulator operational status of the OOBC modulator to non-responsive when the node operational status of the nodes associated with the OOBC modulator is non-responsive.

14. The system of claim 13, wherein the final results processor is further configured for:

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

sending the OOBC modulator display string to a display server; and

wherein the display server is configured for displaying the data elements indicative of the OOBC modulator operational status.

15. The system of claim 9, wherein the plurality of SPUs are set top boxes (CMs) and wherein the CMs are addressable via an out-of-band channel (HSDC), wherein the upstream network component comprises an HSDC modulator and wherein the final results processor is further configured for:

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

setting the HSDC modulator operational status of the HSDC modulator to responsive when the node operational status of at least one node associated with the HSDC modulator is responsive; and

setting the HSDC modulator operational status of the HSDC modulator to non-responsive when the node operational status of the nodes associated with the HSDC modulator is non-responsive.

16. The system of claim 15, wherein the final results processor is further configured for:

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

sending the HSDC modulator display string to a display server; and

wherein the display server is configured for displaying the data elements indicative of the HSDC modulator operational status.