Resilient provider link state bridging (PLSB) virtual private LAN service (VPLS) interworking

• US 9,100,316 B2
• Filed: 09/24/2013
• Issued: 08/04/2015
• Est. Priority Date: 02/09/2008
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Inventors: Bragg, Nigel L., Allan, David, Ashwood Smith, Peter, Ungehagen, Paul
• Primary Examiner(s): Patel, Jay P
• Application Number:
  US14/034,698
• Publication Number:
  US 20140092748A1
• Time in Patent Office: 679 Days
• Field of Search: 370/256, 370/389, 370/390, 370/401
• US Class Current: 1/1
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 45/12 Shortest path evaluation
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering

Abstract

A method of peer interfacing a Link-State controlled network domain with an Ethernet Bridging controlled network domain. A pair of peer attachment points are provided between the Link-State controlled network domain and the Ethernet Bridging domain. The peer attachment points are respective endpoints of a set of one or more LAN segments defined within the Ethernet Bridging domain. The set of LAN segments are represented as a virtual node in the Link-State controlled network domain. The virtual node is represented in the Link-State controlled network domain as connected to each of the peer attachment points via a respective virtual link. The virtual links are configured such that frames to or from an address in the Link-State controlled network domain are forwarded over a tree passing through only one of the peer attachments points.

Claims

1. A method of providing an Ethernet service over a network comprising a Virtual Private LAN Service (VPLS) domain and a Provider Link State Bridging (PLSB) domain, the PLSB domain comprising at least two PLSB networks, the method comprising:

provisioning at least two separate LAN segments dedicated to PLSB operation within the VPLS domain; and

connecting each LAN segment at most once to each of the PLSB networks.

2. The method of claim 1, comprising representing each virtual LAN segment as a respective virtual node in the PLSB domain.

3. The method of claim 2, wherein each virtual node is modelled in Intermediate System to Intermediate System (IS-IS) protocol advertisements as being connected to respective attachment points by respective virtual links.

4. The method of claim 1, wherein each virtual LAN segment is modelled in Intermediate System to Intermediate System (IS-IS) protocol advertisements as a virtual node connected to respective attachment points by respective virtual links.

5. The method of claim 4, comprising the PLSB domain selecting a respective LAN segment to be used for a connection based on a shortest path calculation using the respective costs assigned to the virtual links.

6. The method of claim 1, comprising the PLSB domain selecting a respective LAN segment to be used for a connection based on a shortest path calculation.

7. The method of claim 1, wherein:

connecting each LAN segment at most once to each of the PLSB networks comprises connecting each LAN segment to each of the PLSB networks by a respective link; and

the method comprises assigning a respective cost to each link connecting one of the LAN segments to one of the PLSB networks.

8. The method of claim 7, comprising the PLSB domain selecting a respective LAN segment to be used for a connection based on a shortest path calculation using the respective costs assigned to the links connecting the LAN segments to the PLSB networks.

9. The method of claim 1, wherein connecting each LAN segment at most once to each of the PLSB networks comprises:

defining a respective virtual link to each virtual node in the PLSB domain; and

assigning a respective cost to each virtual link in the PLSB domain.

10. The method of claim 1, comprising each VPLS LAN segment learning connectivity.

11. The method of claim 10, wherein each VPLS LAN segment learning connectivity comprises each VPLS LAN segment learning forwarding information for PLSB B-MAC addresses from frames received by the VPLS LAN segment from the PLSB domain.

12. The method of claim 10, comprising changing connectivity for a particular MAC address in the PLSB domain from one LAN segment of the VPLS domain to another LAN segment of the VLPLS domain without invalidating any MAC forwarding information previously learned in the VPLS domain.

13. The method of claim 10, comprising:

changing connectivity for a particular MAC address in the PLSB domain from a first LAN segment of the VPLS domain to a second LAN segment of the VPLS domain; and

the second LAN segment of the VPLS domain learning forwarding information for the particular MAC address from frames received from the PLSB domain.

14. The method of claim 13, wherein forwarding information for the particular MAC address is not unlearned by the first LAN segment of the VPLS domain.

15. The method of claim 1, comprising dual-homing at least one node of at least one of the at least two PLSB networks onto the two separate LAN segments.

16. The method of claim 1, comprising:

configuring at least two PLSB virtual LANs (VLANs) in the PLSB domain; and

provisioning, for each PLSB VLAN, at least two separate LAN segments dedicated to PLSB operation within the VPLS domain.

17. The method of claim 16, comprising representing each virtual LAN segment as a respective virtual node in the PLSB domain.

18. The method of claim 16, comprising:

defining a respective virtual link to each virtual node in the PLSB domain; and

assigning a respective cost to each virtual link in the PLSB domain.

19. The method of claim 18, comprising the PLSB domain selecting a respective LAN segment to be used for each virtual LAN based on a shortest path calculation using the respective costs assigned to the virtual links.

20. The method of claim 16, wherein:

connecting each LAN segment at most once to each of the PLSB networks comprises connecting each LAN segment to each of the PLSB networks by a respective link, each link connecting the at least two PLSB VLANs to at most one of their respective at least two separate LAN segments; and

the method comprises assigning a respective cost to each link connecting one of the LAN segments to one of the PLSB networks.

21. The method of claim 20, comprising the PLSB domain selecting a respective LAN segment to be used for a connection based on a shortest path calculation using the respective costs assigned to the links connecting the LAN segments to the PLSB networks.

22. The method of claim 16, comprising the PLSB domain balancing load on the LAN segments based on equal-cost multi-path calculations.

23. The method of claim 1, comprising:

configuring at least two virtual LANs (VLANs) in the PLSB domain so that each VLAN appears at all physical interfaces of the PLSB domain; and

load balancing between the at least two LAN segments dedicated to PLSB operation based on PLSB equal-cost multi-path calculations.