Method and apparatus for interworking VPLS and ethernet networks

• US 8,144,715 B2
• Filed: 04/17/2008
• Issued: 03/27/2012
• Est. Priority Date: 08/10/2007
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Rockstar Bidco LP (Rockstar Consortium Inc.)
• Inventors: Ould Brahim, Hamid, Mohan, Dinesh, Allan, David
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Preval, Lionel
• Application Number:
  US12/104,598
• Publication Number:
  US 20090041023A1
• Time in Patent Office: 1,440 Days
• Field of Search: 370/401, 370/395.53, 370/248, 370/289, 709/220
• US Class Current: 370/401
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 12/465 wherein a single frame includes a plurality of VLAN tags
• CPC Class Codes: H04L 12/4654 wherein a VLAN tag represents a customer VLAN, e.g. C-Tag
• CPC Class Codes: H04L 12/4658 wherein a VLAN tag represents a service provider backbone VLAN, e.g. B-Tag, S-Tag
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways

Abstract

To allow seamless interworking between an 802.1ah service instance (ISID) and a VPLS service instance, the AGI value used to signal the setup of the pseudowire portion of the VPLS may carry the ISID value of an associated 802.1ah service instance. This allows the service instance to be identified end-to-end across the Ethernet and VPLS networks using the same value without modifying how the MPLS network operates. The VPLS network will use AGI/AII signaling to set up pseudowires on the MPLS network, but instead of using an AGI value assigned by the MPLS network, the AGI value that is assigned will be taken from the ISID value of the Ethernet frame or from ISIDs registered by the Ethernet network. The AGI message may be given a new type value indicating that the AGI message carries a value that corresponds to the ISID value on an attached Ethernet network. Alternatively, an existing AGI message type may be used to carry the ISID value, and a second type field may be used to indicate that the AGI contains an ISID value.

Claims

1. A method of interworking a MultiProtocol Label Switched (MPLS) network and an Ethernet network, the method comprising the steps of:

associating a Backbone Service Instance Identifier (I-SID) value in the Ethernet network with a service instance in the Ethernet network that is to span between the Ethernet network and the MPLS network;

communicating the I-SID value to an ingress node on the MPLS network;

deriving a MPLS service identifier for the service instance in the MPLS network from the I-SID value that was associated with the service instance in the Ethernet network;

determining a set of egress nodes on the MPLS network from the MPLS service identifier;

signaling, by the ingress node on the MPLS network, a setup of at least one pseudowire for the service instance in the MPLS network;

wherein a value of the MPLS service identifier for the service instance in the MPLS network is the same as the I-SID˜

value that was associated with the service instance in the Ethernet network.

2. The method of claim 1, wherein the service identifier is an Attachment Group Identifier (AGI).

3. The method of claim 1, wherein the I-SID value in the Ethernet network is registered by the Ethernet network at a point of attachment to the MPLS network to allow the Ethernet network to control establishment of the pseudowires in the MPLS network.

4. The method of claim 1, wherein the pseudowire is associated with a Virtual Private LAN Service (VPLS) in the MPLS network.

5. The method of claim 1, wherein the step of signaling the setup of the at least one pseudowire includes transmitting an AGI message having an AGI type value specifying that the AGI value carried in the AGI message is derived from or the same as the I-SID value.

6. The method of claim 1, wherein the step of signaling the setup of the at least one pseudowire includes transmitting an AGI message having a standard AGI message type, but which contains a type field indicating that the AGI message is an I-SID encoding AGI message.

7. The method of claim 2, wherein the AGI value is the same as the I-SID value.

8. The method of claim 2, wherein the AGI value identifies a logical group of forwarders at an egress node on the MPLS network.

9. The method of claim 8, wherein the step of signaling further identifies an Attachment Individual Identifier (AII) that is to be used to forward packets received over the pseudowire.

10. A method of signaling establishment of a pseudowire in a MultiProtocol Label Switching (MPLS) network, the method comprising the steps of:

obtaining identifying information associated with a Flow in an Ethernet network;

deriving an Attachment Group Identifier (AGI) value from the identifying information; and

using the derived AGI value to signal the establishment of a pseudowire in the MPLS network for a service instance in the Ethernet network that is to span between the Ethernet network and the MPLS network;

wherein the AGI value of the pseudowire in the MPLS network has an identifying value within the MPLS network that is the same as the identifying information associated with the Flow in the Ethernet network.

11. The method of claim 10, wherein the identifying information is a Backbone VLAN tag (B-Tag) or Backbone VLAN ID (B-VID) from the flow in the Ethernet Network, and wherein the AGI value is derived from the B-Tag or B-VID.

12. The method of claim 10, wherein the identifying information is a Backbone Service Instance Identifier (I-SID) value associated with a service instance in the Ethernet network, and wherein the AGI value is derived from the I-SID value.

13. The method of claim 12, wherein the I-SID value is registered by the Ethernet network at a point of attachment to the MPLS network.

14. The method of claim 12, wherein the I-SID value is learned from a packet received from the Ethernet network.

15. The method of claim 12, wherein the Ethernet network is implemented to use a link state protocol as a control plane.

16. The method of claim 12, wherein the pseudowire is established on a Label Switched Path through the MPLS network.

17. A network, comprising:

an Ethernet domain implemented to enable service instances identified by Backbone Service Instance Identifier (I-SID) values to be carried on paths through the Ethernet network; and

a MultiProtocol Label Switch (MPLS) domain connected to the Ethernet domain at a point of attachment between the MPLS domain and the Ethernet domain, the MPLS domain being implemented to enable Virtual Private LAN Service (VPLS) pseudowires to be established on Label Switched Paths (LSPs) through the MPLS domain, the pseudowires being established by Attachment Group Identifier (AGI) signaling in the MPLS domain;

wherein I-SID values from the Ethernet domain are used during the AGI signaling in the MPLS domain to allow the I-SID values to be used end-to-end across the network to identify a service instance on both the Ethernet domain and the MPLS domain.

18. The network of claim 17, wherein the I-SID values are registered at the point of attachment between the MPLS domain and the Ethernet domain.

19. The network of claim 17, wherein the I-SID values are learned at the point of attachment between the MPLS domain and the Ethernet domain.

20. The network of claim 17, wherein an AGI message type value used during AGI signaling has a message type indicating that the AGI message carries an I-SID value from the Ethernet domain.

21. The network of claim 17, wherein an AGI message type value used during AGI signaling has a message type is a normal AGI message type value, and wherein the AGI message contains a sub-type value indicating that the AGI message carries an I-SID value from the Ethernet domain.