Map routing technique implemented in access networks

• US 7,085,287 B1
• Filed: 06/27/2001
• Issued: 08/01/2006
• Est. Priority Date: 06/27/2001
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Chapman, John T.
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): TRAN, PHUC H
• Application Number:
  US09/894,852
• Time in Patent Office: 1,861 Days
• Field of Search: 370/312, 370/389, 370/390, 370/392, 370/400, 370/432, 370/473, 370464-468, 725/91, 725/97, 725/103, 725/114, 725/117, 725/138, 725/144, 725/147, 725/4
• US Class Current: 370/468
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 12/2885 Arrangements interfacing with optical systems optical network equipment H04B10/00; optical multiplexers H04J14/05 and H04J14/07
• CPC Class Codes: H04L 12/2896 Distributed processing, e.g. on line cards
• CPC Class Codes: H04L 2101/604 Address structures or formats
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming

Abstract

An improved addressing scheme is disclosed for use in access networks. According to a specific embodiment, upstream and/or downstream channels may be grouped together based upon logical associations rather than physical associations. Further, according to at least one embodiment of the present invention, various techniques are described for routing selected channel MAP messages to appropriate channels and/or nodes within the access network.

Claims

1. A method for forwarding channel MAP messages to selected channels in an access network, the access network including a plurality of upstream and downstream channels for providing communication between network nodes and a Head End of the access network, the Head End including a first physical line card having a first interface for accessing a first portion of the upstream and downstream channels, and a second physical line card having a second interface for accessing a second portion of the upstream and downstream channels, the method comprising:

identifying a first channel MAP message associated with a first upstream channel, the first upstream channel being accessible via the first physical interface, the first channel MAP message including bandwidth allocation map information relating to at least one available timeslot transmission opportunity on the first upstream channel during a first time period;

identifying at least one downstream channel, including a first downstream channel, on which the first channel MAP message is to be transmitted, wherein the first downstream channel is accessible via the second interface; and

forwarding a copy of the first channel MAP message to each of the interfaces associated with each of the identified downstream channels, including the second interface associated with the first downstream channel.

2. The method of claim 1 further comprising forwarding a copy of the first channel MAP message only to each of the interfaces associated with each of the identified downstream channels, wherein each of the identified downstream channels communicates with at least one respective network node configured to communicate with the Head End via the first upstream channel.

3. The method of claim 1 further comprising transmitting the first channel MAP messages only on the identified downstream channels, wherein each of the identified downstream channels communicates with at least one respective network node configured to communicate with the Head End via the first upstream channel.

4. The method of claim 1 wherein each interface corresponds to a respective port on a respective line card.

5. The method of claim 4 wherein the Head End includes a second downstream channel accessible via the first interface, the method first comprising:

transmitting a first copy of the first channel MAP message on the second downstream channel via the first interface; and

transmitting a second copy of the first channel MAP message on the first downstream channel via the second interface.

6. The method of claim 1 wherein said at least one downstream channel identifying includes selecting a particular downstream channel as an identified downstream channel in response to a determination that the particular downstream channel is used to communicate with at least one network node which is configured to use the first upstream channel to communicate with the Head End.

7. The method of claim 1 wherein the identified at least one downstream channel includes only selected downstream channels which are used to communicate with network nodes configured to use the first upstream channel to communicate with the Head End.

8. The method of claim 1 further comprising storing membership information at the Head End, the membership information relating to specific upstream and downstream channels being used by selected network nodes to communicate with the Head End.

9. The method of claim 8 wherein the membership information includes:

a first portion of information for identifying a particular network node;

a second portion of information for identifying an upstream channel used by the network node; and

a third portion of information for identifying a downstream channel used by the network node.

10. The method of claim 1 further comprising:

storing activity information at the Head End, the activity information identifying selected upstream channels in the access network; and

identifying, for each one of the selected upstream channels, any downstream channels which are being used to communicate with network nodes which are configured to communicate with the Head End via one of the selected upstream channels.

11. The method of claim 1 wherein said access network is a cable network implemented in accordance with a DOCSIS standardized protocol, and wherein said network nodes are cable modems.

12. A method for transmitting channel MAP messages to selected channels in an access network, the access network including a plurality of upstream and downstream channels for providing communication between network nodes and a Head End of the access network, the Head End including a first physical line card having a first interface for accessing a first portion of the upstream and downstream channels, and a second physical line card having a second interface for accessing a second portion of the upstream and downstream channels, the method comprising:

identifying a first channel MAP message associated with a first upstream channel, the first upstream channel being accessible via the first physical interface, the first channel MAP message including bandwidth allocation map information relating to at least one available timeslot transmission opportunity on the first upstream channel during a first time period;

identifying particular downstream channels, including a first downstream channel, over which the first channel MAP message is to be transmitted, wherein the first downstream channel is associated with the second interface;

each of the identified downstream channels being used to communicate with at least one respective network node adapted to communicate with the Head End via the first upstream channel; and

transmitting the first channel MAP messages over the identified downstream channels, including the first downstream channel via the second interface.

13. The method of claim 12 further comprising forwarding a copy of the first channel MAP message only to each of the interfaces associated with each of the identified downstream channels, wherein each of the identified downstream channels communicates with at least one respective network configured to communicate with the Head End via the first upstream channel.

14. The method of claim 12 wherein each interface corresponds to a respective port on a respective line card.

15. The method of claim 14 wherein the Head End includes a second downstream channel accessible via the first interface, the method further comprising:

transmitting a first copy of the first channel MAP message on the second downstream channel via the first interface; and

transmitting a second copy of the first channel MAP message on the first downstream channel via the second interface.

16. The method of claim 12 wherein said selected downstream channel identifying includes selecting a particular downstream channel as an identified downstream channel in response to a determination that the particular downstream channel is used to communicate with at least one network node which is configured to use the first upstream channel to communicate with the Head End.

17. The method of claim 12 wherein the identified downstream channels include only selected downstream channels which are used to communicate with network nodes configured to use the first upstream channel to communicate with the Head End.

18. The method of claim 12 wherein said access network is a cable network implemented in accordance with a DOCSIS standardized protocol, and wherein said network nodes are cable modems.

19. In an access network having at least one downstream load sharing group of downstream channels and at least one upstream load sharing group of upstream channels, the group of upstream channels including a first upstream channel accessible via a first interface associated with a first physical linecard, the group of downstream channels including a first downstream channel accessible via a second interface associated with a second physical linecard;

a method for perform channel MAP message forwarding comprising;

identifying a first channel MAP message associated with a first upstream channel, the first upstream channel being accessible via the first physical interface, the first channel MAP message including bandwidth allocation map information relating to least one available timeslot transmission opportunity on the first upstream channel during a first time period;

identifying at least one downstream channel, including a first downstream channel, on which the first channel MAP message is to be transmitted, wherein the first downstream channel is accessible via the second interface; and

forwarding a selected channel MAP message associated with the first upstream channel to selected downstream channels in the downstream load sharing group, including the first downstream channel.

20. The method of claim 19 wherein the selected downstream channels include only those downstream channels which are used to communicate with network nodes that are configured to use the particular upstream channel to communicate with a Head End of the access network.

21. The method of claim 19 wherein said access network is a cable network implemented in accordance with a DOCSIS standardized protocol, and wherein said network nodes are cable modems.

22. A computer program product for forwarding channel MAP messages to selected channels in an access network, the access network including a plurality of upstream and downstream channels for providing communication between network nodes and a Head End of the access network, the Head End including a first physical line card having a first interface for accessing a first portion of the upstream and downstream channels, and a second physical line card having a second interface for accessing a second portion of the upstream and downstream channels, the computer program product comprising:

a computer usable medium having computer readable code embodied therein, the computer readable code comprising;

computer code for identifying a first channel MAP message associated with a first upstream channel, the first upstream channel being accessible via the first physical interface, the first channel MAP message including bandwidth allocation map information relating to at least one available timeslot transmission opportunity on the first upstream channel during a first time period;

computer code for identifying at least one downstream channel, including a first downstream channel, on which the first channel MAP message is to be transmitted, wherein the first downstream channel is accessible via the second interface; and

computer code for forwarding a copy of the first channel MAP message to each of the interfaces associated with each of the identified downstream channels, including the second interface associated with the first downstream channel.

23. The computer program product of claim 22 further comprising computer code for forwarding a copy of the first channel MAP message only to each of the interfaces associated with each of the identified downstream channels, wherein each of the identified downstream channels communicates with at least one respective network node configured to communicate with the Head End via the first upstream channel.

24. The computer program product of claim 22 further comprising computer code for transmitting the first channel MAP messages only on the identified downstream channels, wherein each of the identified downstream channels communicates with at least one respective network node configured to communicate with the Head End via the first upstream.

25. The computer program product of claim 22 wherein each interface corresponds to a respective port on a respective line card.

26. The computer program product of claim 25 further comprising:

computer code for transmitting a first copy of the first channel MAP message on a second downstream channel via the first interface; and

computer code for transmitting a second copy of the first channel MAP message on the first downstream channel via the second interface.

27. The computer program product of claim 22 wherein said downstream channel identifying code includes computer code for selecting a particular downstream channel as an identified downstream channel in response to a determination that the particular downstream channel is used to communicate with at least one network node which is configured to use the first upstream channel to communicate with the Head End.

28. The computer program product of claim 22 wherein the identified at least one downstream channel includes only selected downstream channels which are used to communicate with network nodes configured to use the first upstream channel to communicate with the Head End.

29. The computer program product of claim 22 further comprising computer code for storing membership information at the Head End, the membership information relating to specific upstream and downstream channels being used by selected network nodes to communicate with the Head End.

30. The computer program product of claim 29 wherein the membership information includes:

a first portion of information for identifying a particular network node;

a second portion of information for identifying upstream channel used by the network node; and

a third portion of information for identifying a downstream channel used by the network node.

31. The computer program product of claim 22 further comprising computer code for storing activity information at the Head End, the activity information identifying selected upstream channels in the access network, and further identifying, for each one of the selected upstream channels, any downstream channels which are being used to communicate with network nodes which are configured to communicate with the Head End via one of the selected up channels.

32. The computer program product of claim 22 wherein said access network is a cable network implemented in accordance with a DOCSIS standardized protocol, and wherein said network nodes are cable modems.

33. A system for transmitting channel MAP messages to selected channels in an access network, the access network including a plurality of upstream and downstream channels for providing communication between network nodes and a Head End of the access network, the Head End including a first physical line card having a first interface for accessing a first portion of the upstream and downs channels, and a second physical line card having a second interface for accessing a second portion of the upstream and downstream channels, the system comprising:

means for identifying a first channel MAP message associated with a first upstream channel, the first upstream channel being accessible via the first physical interface, the first channel MAP message including bandwidth allocation map information relating to at least one available timeslot transmission opportunity on the first upstream channel during a first time period;

means for identifying particular downstream channels, including a first downstream channel, over which the first channel MAP message is to be transmitted, wherein the first downstream channel is associated with the second interface;

each of the identified downstream channels being used to communicate with at least one respective network node adapted to communicate with the Head End via the first upstream channel; and

means for transmitting the first channel MAP messages over the identified downstream channels, including the first downstream channel via the second interface.

34. The system of claim 33 further comprising means for forwarding a copy of the first channel MAP message only to each of the interfaces associated with each of the identified downstream channels, wherein each of the identified downstream channels communicates with at least one respective network configured to communicate with the Head End via the first upstream channel.

35. The system of claim 33 wherein each interface corresponds to a respective port on a respective line card.

36. The system of claim 35 further comprising:

means for transmitting a first copy of the first channel MAP message on a second downstream channel via the first interface; and

means for transmitting a second copy of the first channel MAP message on the first downstream channel via the second interface.

37. The system of claim 33 wherein said downstream channel identifying means includes means for selecting a particular downstream channel as an identified downstream channel in response to a determination that the particular downstream channel is used to communicate with at least one network node which is configure to use the first upstream channel to communicate with the Head End.

38. The system of claim 33 wherein the identified downstream channels include only selected downstream channels which are used to communicate with network nodes configured to use the first upstream channel to communicate with the Head End.

39. The system of claim 33 wherein said access network is a cable network implemented in accordance with a DOCSIS standardized protocol, and wherein said network nodes are cable modems.

40. A system for forwarding channel MAP messages to selected channels in an access network, the access network including a plurality of upstream and downstream channels for providing communication between network nodes and a Head End of the access network, the system comprising:

at least one processor,

memory; and

a first physical line card having a first interface for accessing a first portion of the upstream and downstream channels;

the second physical line card having a second interface for accessing a second portion of the upstream and downstream channels;

the system being configured or designed to identify a first channel MAP message associated with a first upstream channel, the first upstream channel being accessible via the first information relating to at least one available timeslot transmission opportunity on the first upstream channel during a first time period;

the system being configured or designed to identify at least one downstream channel, including a first downstream channel, on which the first channel MAP message is to be transmitted, wherein the first downstream channel is accessible via the second interface;

the system being further configured or designed to forward a copy of the first channel MAP message to each of the interfaces associated with each of the identified downstream channels, including the second interface associated with the first downstream channel.

41. The system of claim 40, wherein the system is further configured or designed to forward a copy of the first channel MAP message only to each of the interfaces associated with each of the identified downstream channels, wherein each of the identified downstream channels communicates with at least one respective network node configured to communicate with the Head End via the first upstream channel.

42. The system of claim 40, wherein the system is further configured or designed to transmit the first channel MAP messages only on the identified downstream channels, wherein each of the identified downstream channels communicates with at least one respective network node configured to communicate with the Head End via the first upstream channel.

43. The system of claim 40, wherein each interface corresponds to a respective port on a respective line card.

44. The system of claim 43, wherein the system is further configured or designed to:

currently amended a first copy of the first channel MAP message on a second downstream channel via the first interface; and

transmit a second copy of the first channel MAP message on the first downstream channel via the second interface.

45. The system of claim 40 wherein the system is further configured or design to select a particular downstream channel as an identified downstream channel in response to a determination that the particular downstream channel is used to communicate with at least one network node which is configured to use the first upstream channel to communicate with the Head End.

46. The system of claim 40 wherein the identified at least one downstream channel includes only selected downstream channels which are used to communicate with network nodes configured to use the first upstream channel to communicate with the Head End.

47. The system of claim 40, wherein the processor is configured to store into the memory membership information, the membership information relating to specific upstream and downstream channels being used by selected network nodes to communicate with the Head End.

48. The system of claim 47 wherein the membership information includes:

a first portion of information for identifying a particular network node;

a second portion of information for identifying an upstream channel used by the network node; and

a third portion of information for identifying a downstream channel used by the network node.

49. The system of claim 40, wherein the processor is configured to store into the memory activity information, the activity information identifying selected upstream channels in the access network, and further idealizing, for each one of the selected upstream channels, any downstream channels which are being used to communicate with network nodes which are configured to communicate with the Head End via one of the selected upstream channels.

50. The system of claim 40 wherein said access network is a cable network implemented in accordance with a DOCSIS standardized protocol, and wherein said network nodes are cable modems.

51. An access network comprising:

a plurality of network nodes;

a Head End configured or designed to communicate with the plurality of nodes via a plurality of upstream and downstream channels, the Head End including;

at least one processor;

memory;

a first physical line card having a first interface for accessing a first portion of the upstream and downstream channels; and

a second physical line card having a second interface for accessing a second portion of the upstream and downstream channels

the access network being configured or designed to identify a first channel MAP message associated with a first upstream channel, the first upstream channel being accessible via the first physical interface, the first channel MAP message including bandwidth allocation map information relating to at least one available timeslot transmission opportunity on the first upstream channel during a first time period;

the access network being further configured or designed to identify particular downs channels, including a first downstream channel, over which the first channel MAP message is to be transmitted, wherein the first downstream channel is associated with the second interface;

each of the identified downstream channels being used to communicate with at least one respective network node adapted to communicate with the Head End via the first upstream channel; and

the access network being further configured or designed to transmit the first channel MAP messages over the identified downs channels, including the first downstream channel via the second interface.

52. The access network of claim 51, wherein the access network is further configured or designed to forward a copy of the first channel MAP message only to each of the interfaces associated with each of the identified downstream channels, wherein each of the identified downstream channels communicates with at least one respective network configured to communicate with the Head End via the first upstream channel.

53. The access network of claim 51 wherein each interface corresponds to a respective port on a respective line card.

54. The access network of claim 53, wherein the access network is further configured or designed to:

transmit a first copy of the first channel MAP message on a second downstream channel via the first interface; and

transmit a second copy of the first channel MAP message on the first downstream channel via the second interface.

55. The access network of claim 51, wherein the access network or is further configured or designed to select a particular downstream channel as an identified downstream channel in response to a determination that the particular downstream channel is used to communicate with at least one network node which is configured to use the first upstream channel to communicate with the Head End.

56. The access network of claim 51 wherein the identified downstream channels include only selected downstream channels which are used to communicate with network nodes configured to use the first upstream channel to communicate with the Head End.

57. The access network of claim 51 wherein said access network is a cable network implemented in accordance with a DOCSIS standardized protocol, and wherein said network nodes are cable modems.