Scalable system and method for DSL subscriber traffic over an Ethernet network

• US 9,088,669 B2
• Filed: 04/28/2005
• Issued: 07/21/2015
• Est. Priority Date: 04/28/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Sajassi, Ali
• Primary Examiner(s): Weidner, Timothy J
• Application Number:
  US11/117,249
• Publication Number:
  US 20060245435A1
• Time in Patent Office: 3,736 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04L 12/2881 IP/Ethernet DSLAM
• CPC Class Codes: H04L 12/4662 wherein a VLAN tag represents a service instance, e.g. I-SID in PBB
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04M 11/062 using different frequency bands for speech and other data

Abstract

A system and method for identifying and forwarding traffic to/from Digital Subscriber Line Access Multiplexer (DSLAM) devices and feature servers without ambiguity includes a user-facing provider edge (u-PE) device that receives a customer frame from a DSLAM device, the customer frame being of a first format that includes a first Virtual Local Area Network (VLAN) tag of a first bit length. The first VLAN tag identifies a Digital Subscriber Line (DSL) subscriber. The customer frame is re-formatted by the u-PE device such that the first VLAN tag is mapped to a second VLAN tag of a second bit length greater than the first bit length, the second VLAN tag identifying a service instance of the Ethernet access network. The u-PE device encapsulating the customer frame inside a provider frame, with a provider source Media Access Control (MAC) address represents a MAC address associated with the DSLAM, and a provider destination MAC address represents a MAC address of a destination device.

Claims

1. A processor-implemented method of operation for a user-facing provider edge (u-PE) device of an Ethernet access network, the method comprising:

receiving a customer frame from a Digital Subscriber Line Access Multiplexer (DSLAM) device, the customer frame being of a first format that includes a first Virtual Local Area Network (VLAN) tag, the first VLAN tag including a VLAN identifier portion having a first predetermined bit length identifying a Digital Subscriber Line (DSL) subscriber; and

re-formatting the customer frame into a second format, wherein the first VLAN identifier portion is mapped to a second VLAN identifier portion of a second VLAN tag, the second VLAN identifier portion having a second predetermined bit length greater than the first predetermined bit length, the second VLAN tag identifying a service instance of the Ethernet access network, in the second format the customer frame being encapsulated inside a provider frame, wherein a provider source Media Access Control (MAC) address represents a MAC address associated with the DSLAM, and a provider destination MAC address represents a MAC address of a destination device.

2. The processor-implemented method of claim 1 wherein the destination device is a feature server.

3. The processor-implemented method of claim 1 wherein reformatting the customer frame includes adding a third VLAN tag that specifies a broadcast domain of the Ethernet access network.

4. The processor-implemented method of claim 3 wherein the broadcast domain corresponds to a DSL service type.

5. The processor-implemented method of claim 3 wherein the broadcast domain corresponds to a service node.

6. A processor-implemented method of operation for a Digital Subscriber Line Access Multiplexer (DSLAM) device coupled to an Ethernet access network, comprising:

encapsulating a customer frame inside a provider frame, wherein a provider source Media Access Control (MAC) address represents a MAC address associated with the DSLAM device, and a provider destination MAC address represents a MAC address of a service node; and

adding a first Virtual Local Area Network (VLAN) tag having a VLAN identifier bit field that identifies a service instance of the Ethernet access network and other bit fields not identifying the service instance of the Ethernet access network, the VLAN identifier bit field being 20 bits long.

7. The processor-implemented method of claim 6 further comprising:

adding a second VLAN tag that specifies a broadcast domain of the Ethernet access network.

8. The processor-implemented method of claim 7 wherein the broadcast domain corresponds to a Digital Subscriber Line (DSL) network service type.

9. A user-facing provider edge (u-PE) device for association with an Ethernet access network, the u-PE device comprising:

a port to receive a customer frame from a Digital Subscriber Line Access Multiplexer (DSLAM) device, the customer frame being of a first format that includes a first Virtual Local Area Network (VLAN) tag including a first VLAN identifying portion of a first predetermined bit length identifying a Digital Subscriber Line (DSL) subscriber; and

a processor operable to re-format the customer frame into a second format, wherein the VLAN identifying portion of the first VLAN tag is mapped to a VLAN identifying portion of a second VLAN tag, the second VLAN identifying portion having a second predetermined bit length greater than the first predetermined bit length and identifying a service instance of the Ethernet access network, in the second format the customer frame being encapsulated inside a provider frame, wherein a provider source Media Access Control (MAC) address represents a MAC address associated with the DSLAM, and a provider destination MAC address represents a MAC address of a destination device.

10. The u-PE device of claim 9 wherein the second format includes a third VLAN tag that specifies a broadcast domain of the Ethernet access network.

11. The u-PE device of claim 10 wherein the broadcast domain corresponds to a DSL service type.

12. A Digital Subscriber Line Access Multiplexer (DSLAM) device for connection to an Ethernet access network, comprising:

a port to receive a, customer frame; and

a processor operable to encapsulate the customer frame inside a provider frame, wherein a provider source Media Access Control (MAC) address represents a MAC address associated with the DSLAM device, and a provider destination MAC address represents a MAC address of a service node, the processor being further operable to add a first Virtual Local Area Network (VLAN) tag having a first VLAN identifier portion that identifies a service instance of the Ethernet access network, the processor being further operable to add a second VLAN tag having a second VLAN identifier portion that specifies a broadcast domain of the Ethernet access network.

13. The DSLAM device of claim 12 wherein the broadcast domain corresponds to a Digital Subscriber Line (DSL) service type.

14. A device for connection to an Ethernet access network, comprising:

a port to receive a customer frame; and

a processor operable to encapsulate the customer frame inside a provider frame, wherein a provider source Media Access Control (MAC) address represents a MAC address associated with a Digital Subscriber Line Access Multiplexer (DSLAM) device, and a provider destination MAC address represents a MAC address of a service node, the processor being further operable to add a Virtual Local Area Network (VLAN) tag having a VLAN identifier portion that identifies a service instance of the Ethernet access network and also having other portions that do not identify a service instance of the Ethernet access network, the VLAN identifier portion being greater than 12 bits long.

15. An Ethernet access network, comprising:

a user-facing provider edge (u-PE) device configured to receive a customer frame from a Digital Subscriber Line Access Multiplexer (DSLAM) device, the customer frame including a first Virtual Local Area Network (VLAN) tag that includes a first VLAN identifier portion that identifies a Digital Subscriber Line (DSL) subscriber and that also includes other portions that do not identify the DSL subscriber, the u-PE device including means for encapsulating the customer frame inside a provider frame, wherein a provider source Media Access Control (MAC) address represents a MAC address associated with a Digital Subscriber Line Access Multiplexer (DSLAM) device, and a provider destination MAC address represents a MAC address of a service node, the means also for adding a second VLAN tag having a second VLAN identifier portion that identifies a service instance of the Ethernet access network, the second VLAN tag also including other portions that do not identify a service instance of the Ethernet access network, the second VLAN identifier portion being 20 bits long; and

a network-facing provider edge (u-PE) device configured to forward the packet to the service node.