Self-bootstrapping BFD session over MPLS LSP

• US 20160036695A1
• Filed: 08/04/2014
• Published: 02/04/2016
• Est. Priority Date: 08/04/2014
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Mirsky, Gregory, Tantsura, Evgeny
• Granted Patent: US 9,509,599 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 43/20 the monitoring system or the monitored elements being virtualised, abstracted or software-defined entities, e.g. SDN or NFV
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/507 Label distribution

Abstract

A method is implemented by a network device in a network implementing penultimate hop popping (PHP) for Internet Protocol (IP)/Multi-Protocol Label Swapping (MPLS). The network has a plurality of nodes. The method establishes a bi-directional forwarding detection (BFD) session between an active node and a passive node of an MPLS label switched path (LSP) without an out of band bootstrapping process. In this method the network device is the passive node. The passive node generates a My Discriminator for the passive node, where the Your Discriminator is empty and the source label and My Discriminator are known to the passive node. The passive node sends further BFD control packets to the active node that include the generated My discriminator for the passive node.

Claims

1. A method implemented by a network device in a network implementing penultimate hop popping (PHP) for Internet Protocol (IP)/Multi-Protocol Label Swapping (MPLS), the network having a plurality of nodes, the method to establish a bi-directional forwarding detection (BFD) session between an active node and a passive node of an MPLS label switched path (LSP) without an out of band bootstrapping process, where the network device is the passive node, the method comprising the steps of:

receiving an MPLS packet including a BFD control packet, a source label and a source label indicator;

accessing the My Discriminator of the BFD control packet, Your Discriminator of the BFD control packet and the source label of the MPLS packet;

checking whether a BFD session exists with the Your Discriminator;

looking up whether the source label is known, where no BFD session exists with the Your Discriminator;

looking up whether the My Discriminator is known, where the source label is known;

generating a My Discriminator for the passive node, where the source label is known and the My Discriminator is not known;

establishing the BFD session for a forwarding equivalency class (FEC) identified in the source label; and

sending a second BFD control packet in a second MPLS packet to the active node, where the second BFD control packet includes the generated My discriminator for the passive node.

2. The method of claim 1, further comprising:

creating a BFD state machine for the BFD session.

3. The method of claim 1, wherein the source label indicator indicates that a next label is the source label containing the FEC for the BFD session.

4. The method of claim 1, wherein the network implements segment routing.

5. The method of claim 1, further comprising:

dropping the received MPLS packet where the lookup of the source label and My Discriminator indicate the BFD session is not known.

6. A network device in a network implementing penultimate hop popping (PHP) for Internet Protocol (IP)/Multi-Protocol Label Swapping (MPLS), the network having a plurality of nodes, the network device to execute a method to establish a bi-directional forwarding detection (BFD) session between an active node and a passive node of an MPLS label switched path (LSP) without an out of band bootstrapping process, where the network device is the passive node, the network device comprising:

a non-transitory machine-readable storage medium to store a BFD bootstrap module and MPLS module; and

a network processor communicatively coupled to the non-transitory machine-readable storage medium, the network processor to execute the BFD bootstrap module, the BFD bootstrap module configured to receive an MPLS packet including a BFD control packet, a source label and a source label indicator, to access the My Discriminator of the BFD control packet, Your Discriminator of the BFD control packet and the source label of the MPLS packet, to check whether a BFD session exists with the Your Discriminator, to look up whether the source label is known, where no BFD session exists with the Your Discriminator, to look up whether the My Discriminator is known, where the source label is known, to generate a My Discriminator for the passive node, where the source label and My Discriminator are known, to establish the BFD session for a forwarding equivalency class (FEC) identified in the source label, and to send a second BFD control packet in a second MPLS packet to the active node, where the second BFD control packet includes the generated My discriminator for the passive node.

7. The network device of claim 6, wherein the network processor is configured to execute the BFD bootstrap module which is further configured to create a BFD state machine for the BFD session.

8. The network device of claim 6, wherein the source label indicator indicates that a next label is a source label containing the FEC for the BFD session.

9. The network device of claim 6, wherein the network implements segment routing.

10. The network device of claim 6, wherein the network processor is configured to execute the BFD bootstrap module which is further configured to drop the received MPLS packet where the lookup of the source label and My Discriminator indicate the BFD session is not known.

11. A computing device implementing a plurality of virtual machines for implementing network function virtualization (NFV), wherein a virtual machine from the plurality of virtual machines is configured to execute a method, where the computing device is in a network implementing penultimate hop popping (PHP) for Internet Protocol (IP)/Multi-Protocol Label Swapping (MPLS), the network having a plurality of nodes, the method to establish a bi-directional forwarding detection (BFD) session between an active node and a passive node of an MPLS label switched path (LSP) without an out of band bootstrapping process, where the computing device is the passive node, the computing device comprising:

a non-transitory machine-readable storage medium to store a BFD bootstrap module, MPLS module and BFD module; and

a processor communicatively coupled to the non-transitory machine-readable storage medium, the processor to execute the BFD bootstrap module, the BFD bootstrap module configured to receive an MPLS packet including a BFD control packet, a source label and a source label indicator, to access the My Discriminator of the BFD control packet, Your Discriminator of the BFD control packet and the source label of the MPLS packet, to check whether a BFD session exists with the Your Discriminator, to look up whether the source label is known, where no BFD session exists with the Your Discriminator, to look up whether the My Discriminator is known, where the source label is known, where no BFD session exists with the Your Discriminator, to generate a My Discriminator for the passive node, where the source label and My Discriminator are known, to establish the BFD session for a forwarding equivalency class (FEC) identified in the source label, and to send a second BFD control packet in a second MPLS packet to the active node, where the second BFD control packet includes the generated My discriminator for the passive node.

12. The computing device of claim 11, wherein the network processor is configured to execute the BFD bootstrap module which is further configured to create a BFD state machine for the BFD session.

13. The computing device of claim 11, wherein the source label indicator indicates that a next label is a source label containing the FEC for the BFD session.

14. The computing device of claim 11, wherein the network implements segment routing.

15. The computing device of claim 11, wherein the network processor is configured to execute the BFD bootstrap module which is further configured to drop the received MPLS packet where the lookup of the source label and My Discriminator indicate the BFD session is not known.

16. A control plane device configured to implement at least one centralized control plane for a software defined network (SDN), the centralized control plane configured to execute a method, where the computing device is in a network implementing penultimate hop popping (PHP) for Internet Protocol (IP)/Multi-Protocol Label Swapping (MPLS), the network having a plurality of nodes, the method to establish a bi-directional forwarding detection (BFD) session between an active node and a passive node of an MPLS label switched path (LSP) without an out of band bootstrapping process, where the control plane device is the passive node, the control plane device comprising:

a non-transitory machine-readable storage medium to store a BFD bootstrap module, MPLS module and BFD module; and

a network processor communicatively coupled to the non-transitory machine-readable storage medium, the network processor to execute the BFD bootstrap module, the BFD bootstrap module configured to receive an MPLS packet including a BFD control packet, a source label and a source label indicator, to access the My Discriminator of the BFD control packet, Your Discriminator of the BFD control packet and the source label of the MPLS packet, to check whether a BFD session exists with the Your Discriminator, to look up whether the source label is known, where no BFD session exists with the Your Discriminator, to look up whether the My Discriminator is known, where the source label is known, to generate a My Discriminator for the passive node, where the source label and My Discriminator are known, to establish the BFD session for a forwarding equivalency class (FEC) identified in the source label, and to send a second BFD control packet in a second MPLS packet to the active node, where the second BFD control packet includes the generated My discriminator for the passive node.

17. The control plane device of claim 16, wherein the network processor is configured to execute the BFD bootstrap module which is further configured to create a BFD state machine for the BFD session.

18. The control plane device of claim 16, wherein the source label indicator indicates that a next label is a source label containing the FEC for the BFD session.

19. The control plane device of claim 16, wherein the network implements segment routing.

20. The control plane device of claim 16, wherein the network processor is configured to execute the BFD bootstrap module which is further configured to drop the received MPLS packet where the lookup of the source label and My Discriminator indicate the BFD session is not known.