System and method for managing communications in an access network

• US 8,693,323 B1
• Filed: 06/01/2004
• Issued: 04/08/2014
• Est. Priority Date: 04/05/2004
• Status: Active Grant

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: Verizon Business Global LLC (Verizon Communications Inc.)
• Inventors: McDysan, David E.
• Primary Examiner(s): Sefcheck, Gregory
• Application Number:
  US10/858,525
• Time in Patent Office: 3,598 Days
• Field of Search: None
• US Class Current: 370/230
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42

Abstract

System and method for managing communications in an access network is provided. The system and method utilizes carrier-tagged paths established between communicatively coupled terminating elements, such as a service or customer edge and network elements, such as a building aggregator, layer 2 switch, or the like. The carrier-tagged paths may be nested within one another, and carrier-tagged paths may be aggregated together to simplify switching. Carrier-tagged flows carried over the carrier-tagged paths include one or more carrier tags prepended to terminating element traffic. For example, in an embodiment, inbound carrier-tagged flows from multiple sources destined for a common service edge may be merged by prepending a common carrier tag. In another embodiment, outbound carrier-tagged flows are nested within other carrier-tagged flows.

Claims

1. A method for providing communications in an access network, the method comprising:

receiving on a first interface a first packetized communication via a carrier-tagged flow, each packet of the first packetized communication having a plurality of carrier tags prepended to a carrier-tagged flow payload;

determining a second interface on which the first packetized communication is to be routed, the second interface being based upon the first interface and an outermost carrier tag;

routing the first packetized communication to the second interface,

wherein the one or more carrier tags are pushed on each packet of the first packetized communication as the first packetized communication travels through the access network.

2. The method of claim 1, further comprising popping one or more carrier tags from the first packetized communication as the first packetized communication travels toward a destination network element.

3. The method of claim 2, wherein the network element comprises a service edge.

4. The method of claim 2, wherein the network element comprises a customer edge.

5. The method of claim 1, further comprising switching one or more carrier tags of the first packetized communication as the first packetized communication travels toward a destination network element.

6. A method for providing communications in an access network, the method comprising:

receiving a first carrier-tagged flow from a first network device, the first carrier-tagged flow having one or more packets, each packet having a plurality of carrier tags;

determining a first carrier-tagged path to which the first carrier-tagged flow is to be routed, the determining being based at least in part on a first outermost carrier tag of the carrier tags;

routing the first carrier-tagged flow to the first carrier-tagged path; and

switching the first outermost label with a second outermost label.

7. The method of claim 6, wherein the method is performed by a layer 2 switch.

8. The method of claim 6, wherein the first network device comprises a building aggregator.

9. The method of claim 6, wherein the determining is performed in part by traversing a forwarding information base until a physical interface is determined.

10. The method of claim 6, wherein the second outermost label is a tunnel label.

11. The method of claim 6, further comprising:

receiving a second carrier-tagged flow from a second network device, the second carrier-tagged flow having one or more packets, each packet having one or more carrier tags; and

merging the first carrier-tagged flow and the second carrier-tagged flow by prepending a common carrier tag to each packet of the first carrier-tagged flow and the second carrier-tagged flow prior to the routing.

12. A method for providing communications in an access network, the method comprising:

receiving a first carrier-tagged flow from a first network device, the first carrier-tagged flow having one or more packets, each packet having one or more carrier tags;

determining a second network device to which the first carrier-tagged flow is to be routed, the determining being based at least in part on a first outermost carrier tag of the carrier tags;

pushing a second outermost carrier tag onto each packet of the first carrier-tagged flow, the second outermost carrier tag indicating a second carrier-tagged flow within which the first carrier-tagged flow is nested; and

routing the second carrier-tagged flow to the second network device.

13. The method of claim 12, wherein the method is performed by a layer 2 switch.

14. The method of claim 12, wherein the first network device comprises a building aggregator.

15. The method of claim 12, wherein the second network device comprises a layer 2 switch.

16. The method of claim 12, wherein the determining is performed in part by traversing a forwarding information base until a physical interface is determined.

17. The method of claim 12, further comprising switching the first outermost label with a third outermost label.

18. The method of claim 12, wherein the first outermost label comprises a pseudowire label.

19. The method of claim 12, wherein the second outermost label comprises a tunnel label.

20. The method of claim 12, further comprising:

receiving a second carrier-tagged flow from a second network device, the second carrier-tagged flow having one or more packets, each packet having one or more carrier tags; and

merging the first carrier-tagged flow and the second carrier-tagged flow by prepending a common carrier tag to each packet of the first carrier-tagged flow and the second carrier-tagged flow prior to the routing.

21. The method of claim 12, wherein the second outermost carrier tag is determined based at least in part on a destination of the second carrier-tagged flow.

22. A method for providing communications in an access network, the method comprising:

receiving communications from a first network device, the communications comprising one or more packets;

determining a terminating element to which the communications are to be sent;

pushing a first carrier tag on each packet of the communications, the first carrier tag indicating a first carrier-tagged flow;

pushing a second carrier tag on each packet of the communications, the second carrier tag indicating a second carrier-tagged flow, the first carrier-tagged flow being nested within the second carrier-tagged flow; and

transmitting each packet on the second carrier-tagged flow to a second network element.

23. The method of claim 22, wherein the first network device comprises a customer edge.

24. The method of claim 22, wherein the first network device comprises a building aggregator.

25. The method of claim 22, wherein the first network device comprises a first customer edge and the terminating element comprises a second customer edge.

26. The method of claim 22, wherein the second network device comprises a layer 2 switch.

27. The method of claim 22, wherein the first carrier-tagged flow comprises a pseudowire.

28. The method of claim 27, wherein the first carrier tag comprises a pseudowire label.

29. The method of claim 22, wherein the second carrier-tagged flow comprises a tunnel.

30. The method of claim 29, wherein the second carrier tag comprises a tunnel encapsulation.

31. The method of claim 22, further comprising:

receiving a third carrier-tagged flow from a third network device, the third carrier-tagged flow having one or more packets, each packet having one or more carrier tags; and

merging the first carrier-tagged flow and the third carrier-tagged flow by prepending the second carrier tag to each packet of the first carrier-tagged flow and the third carrier-tagged flow prior to the transmitting.

32. The method of claim 22, wherein the pushing the first carrier tag and the pushing the second carrier tag is performed in part by traversing an information base until a physical interface is determined.

33. The method of claim 22, further comprising pushing a first number of carrier tags onto the second carrier-tagged flow, the first number being dependent upon how many times a lookup table is traversed until a physical interface is determined.

34. The method of claim 22, wherein the terminating element comprises a service edge.

35. The method of claim 22, wherein the terminating element comprises a customer edge.

36. A method for providing communications in an access network, the method comprising:

receiving a first packetized communications from a first network device, the first packetized communications comprising one or more packets, each packet having a first carrier-tag and a second carrier tag prepended to a carrier-tagged flow payload;

popping the first carrier tag thereby creating a second packetized communications comprising the second carrier tag prepended to the carrier-tagged flow payload;

determining a terminating element to which the second packetized communications are to be sent, the determining being based at least in part on the first carrier tag; and

transmitting the second packetized communications to the terminating element.

37. The method of claim 36, wherein the first network device comprises a layer 2 switch.

38. The method of claim 36, wherein the first packetized communications is received via a first carrier-tagged flow.

39. The method of claim 36, wherein the first carrier tag comprises a tunnel encapsulation.

40. The method of claim 36, wherein the second packetized communications is transmitted via a second carrier-tagged flow.

41. The method of claim 36, wherein the second carrier tag comprises a pseudowire label.

42. The method of claim 36, wherein the terminating element comprises a service edge.

43. The method of claim 36, wherein the terminating element comprises a customer edge.

44. A method for providing communications in an access network, the method comprising:

receiving a first carrier-tagged flow from a first network device, the first carrier-tagged flow having one or more packets, each packet having a first carrier tag and a second carrier tag prepended to a carrier-tagged flow payload;

popping the first carrier tag from the each packet of the first carrier-tagged flow, thereby creating a second carrier-tagged flow comprising the second carrier tag prepended to the carrier-tagged flow payload;

determining a destination network element to which the second carrier-tagged flow is to be routed, the destination network element being based at least in part on the first carrier tag; and

routing the second carrier-tagged flow to the destination network element.

45. The method of claim 44, wherein the method is performed by a layer 2 switch.

46. The method of claim 44, wherein the first network device comprises a service edge.

47. The method of claim 44, wherein the first network device comprises a building aggregator.

48. The method of claim 44, wherein the first network device comprises a customer edge.

49. The method of claim 44, wherein the first network device comprises a layer 2 switch.

50. The method of claim 44, wherein the destination network element comprises a building aggregator.

51. The method of claim 44, wherein the first carrier-tagged flow is nested within another carrier-tagged flow.

52. The method of claim 44, wherein the first carrier tag comprises a tunnel label.

53. The method of claim 44, wherein the second carrier tag comprises a pseudowire label.

54. The method of claim 44, wherein the determining is performed in part by traversing an forwarding information base until a physical interface is determined.

55. The method of claim 44, further comprising pushing a first number of carrier tags onto the second carrier-tagged flow, the first number being dependent upon how many times a lookup table is traversed until a physical interface is determined.

56. A method for providing communications in an access network, the method comprising:

receiving a first carrier-tagged flow from a first network device, the first carrier-tagged flow comprising a first carrier tag prepended to a first nested carrier-tagged flow and a second carrier tag prepended to a second nested carrier tagged flow;

popping the first carrier tag from the first nested carrier-tagged flow;

determining a first destination network element to which the first nested carrier-tagged flow is to be routed, the determining the first destination network element being based at least in part on the first carrier tag;

routing the first nested carrier-tagged flow to the first destination network element;

popping the second carrier tag from the second nested carrier-tagged flow;

determining a second destination network element to which the second nested carrier-tagged flow is to be routed, the determining the second destination network element being based at least in part on the second carrier tag; and

routing the second nested carrier-tagged flow to the second destination network element.

57. The method of claim 56, wherein the method is performed by a layer 2 switch.

58. The method of claim 56, wherein the first network device is a terminating element.

59. The method of claim 56, wherein the first network device comprises a service edge.

60. The method of claim 56, wherein the first network device comprises a customer edge.

61. The method of claim 56, wherein the first network device comprises a building aggregator.

62. The method of claim 56, wherein the first network device comprises a layer 2 switch.

63. The method of claim 56, wherein the first destination network element comprises a building aggregator.

64. The method of claim 56, wherein the second destination network element comprises a building aggregator.

65. The method of claim 56, wherein the first destination network element and the second destination network element are different network elements.

66. The method of claim 56, wherein the first carrier-tagged flow comprises a tunnel.

67. The method of claim 56, wherein the first nested carrier-tagged flow and the second nested carrier-tagged flow comprises pseudowires nested within a tunnel.

68. The method of claim 56, wherein the determining the first destination network element and the determining the second destination network element are performed in part by traversing an forwarding information base until a physical interface is determined.

69. A method for providing communications in an access network, the method comprising:

receiving a carrier-tagged flow from a first network device, the carrier-tagged flow comprising one or more packets, each packet comprising at least a first carrier tag and a second carrier tag prepended to a carrier-tagged flow payload;

popping the first carrier tag from each packet;

determining a terminating element to which the communications are to be sent, the determining being based at least in part on the first carrier tag; and

transmitting the carrier-tagged flow payload to a customer edge.

70. The method of claim 69, wherein the first network device comprises a service edge.

71. The method of claim 69, wherein the first network device comprises the customer edge.

72. The method of claim 69, wherein the terminating element comprises a service edge.

73. The method of claim 69, wherein the terminating element comprises the customer edge.

74. The method of claim 69, wherein the terminating element comprises a building aggregator.

75. The method of claim 69, wherein the first network device comprises a layer 2 switch.

76. The method of claim 69, wherein the method is performed by a layer 2 switch.

77. The method of claim 69, wherein the carrier-tagged flow comprises a pseudowire.

78. The method of claim 69, wherein the carrier-tagged flow comprises a tunnel.

79. The method of claim 69, wherein the carrier tag comprises a pseudowire label.

80. The method of claim 69, wherein the carrier tag comprises a tunnel label.

81. The method of claim 69, wherein the determining is performed in part by traversing a forwarding information base until a physical interface is determined.

82. A method for implementing a proxy function by a first network element, the method comprising:

receiving by the first network element communications from a second network element, the first network element performing for the first terminating element a first forwarding proxy function that includes pushing a first carrier tag on the communications from the second network element to form a first carrier-tagged flow;

pushing a second carrier tag on the first carrier-tagged flow to form a second carrier-tagged flow;

determining a third network element to which the second carrier-tagged flow is to be routed, the determining being based at least in part on the second carrier tag; and

sending the second carrier-tagged flow to the third network element.

83. The method of claim 82, wherein the second network element comprises a building aggregator.

84. The method of claim 82, wherein the second network element comprises a layer 2 switch.

85. The method of claim 82, wherein the first network element comprises a layer 2 switch.

86. The method of claim 82, wherein the communications comprise packetized communications.

87. The method of claim 82, wherein the first carrier tag comprises a pseudowire label.

88. The method of claim 82, wherein the second carrier tag comprises a tunnel label.

89. A method for establishing carrier-tagged paths within an access network, the method comprising:

establishing a carrier-tagged path between a first network element and a second network element, the carrier-tagged path being identified by a first carrier tag;

establishing a first control link between the first and second network element;

establishing control links between the first network element and one or more customer terminating equipments;

receiving a control message by the first network element from the second network element, the control message comprising at least an identifier of a specific customer terminating equipment;

distributing a second carrier tag over the control link between the first network element and the specific customer terminating equipment;

receiving communications by the first network element from the customer terminating equipment, the communications including the second carrier tag; and

sending the communications to the second network element on the carrier-tagged path.

90. The method of claim 89 further comprising associating the second carrier tag with the first carrier tag in the customer terminating equipment.

91. The method of claim 89, wherein the associating is performed by creating an entry in an information base.

92. The method of claim 89, wherein the distributing is performed in part by using Label Distribution Protocol between the first network element and the customer terminating equipment.

93. The method of claim 89, wherein the customer terminating equipment comprises a building aggregator.

94. The method of claim 89, wherein the carrier-tagged path comprises a tunnel.

95. The method of claim 89, wherein the carrier-tagged path comprises a pseudowire.

96. The method of claim 89, wherein the associating is performed by creating an entry in an information base.

97. The method of claim 89, wherein the distributing is performed in part by using Label Distribution Protocol between the first network element and the second network element.

98. The method of claim 89, wherein the distributing is performed in part by using Label Distribution Protocol between a layer 2 switch and a building aggregator.