Ciena Corporation

Sudipta Das

Aditya Mittal

Pankaj Verma

Udo Mircea Neustadter

Atul Sharma

Ashutosh Aggarwal

Ritu Chawla

A node is configured to operate in a Segment Routing (SR) over Internet Protocol version 6 (SRv6) network, and the node includes circuitry configured to determine a Segment Identifier (SID) list for a forward path in the SRv6 network and SID list for a reverse path in the SRv6 network; and transmit a monitoring packet on the forward path including a Segment Routing Header (SRH) with the SID list for the forward path, and further including the SID list for the reverse path in the monitoring packet, for a SRH of a reply to the monitoring packet. The circuitry can be further configured to receive the reply to the monitoring packet, with the reply having been on a same or different tunnel as the monitoring packet, for monitoring liveliness thereof.

Segment routing SRv6 S-BFD and ping replies having deterministic reply path

Systems and methods at a reflector node include steps of receiving a request from an initiator node in the network, the request having been sent in a forward direction from the initiator node to the reflector node to discover a reverse path in a reverse direction from the reflector node to the initiator node, and transmitting a reply to the initiator node with one or more reverse Segment Routing (SR) policies that meet one or more path constraint parameters in the request. The reply can include associated Segment Identifiers (SIDs) for the one or more reverse SR policies. The steps can further include implementing one of Bidirectional Forwarding Detection (BFD) or a Multi-Protocol Label Switching (MPLS) Ping procedure with the initiator node, sent over one of the one or more reverse SR policies.

Discovering a reverse path for initiating bidirectional forwarding detection (BFD)

Systems and methods for performing connectivity checks, such as Seamless Bidirectional Forwarding Detection (S-BFD), are provided. A method, according to one implementation, includes receiving, at a responding node, an entry configured to call for a modification of an identification element (from an old identifier value to a new identifier value) used for identifying the responding node with respect to other nodes of a network. The old and new identifier values are cached in a memory device. Also, the method includes providing a reply packet back to an initiating node in response to receipt of a request packet from the initiating node. The request packet is related to a connectivity check for testing the connectivity between the initiating node and the responding node. In addition, the request packet is able to identify the responding node by either the old identifier value or the new identifier value.

Graceful transition in a connectivity test when a discriminator is changed in a seamless bidirectional forwarding detection (S-BFD) reflector node

Systems and methods for enabling Bidirectional Forwarding Detection (BFD) over a selected reverse path are provided. A process, according to one implementation, include sending an echo request in a forward direction from an initiator node to a reflector node. For example, the initiator node and reflector node may be configured to operate in a network having no or different centralized controller that manages both the initiator node and reflector node. The echo request may be sent to the reflector node to discover a reverse path in a reverse direction from the reflector node to the initiator node. Also, the reverse path is discovered for the purpose of initiating a Bidirectional Forwarding Detection (BFD) or Multi-Protocol Label Switching (MPLS) Ping procedure.

Systems and methods for monitoring the continuity between endpoints in a network are provided. A process, according to one implementation, includes entering a first list of one or more Segment Identifiers (SIDs) into a Bidirectional Forwarding Detection (BFD) request packet, the first list of one or more SIDs defining a Segment-Routing Traffic-Engineering (SR-TE) forward path from a source node to a destination node. The process also includes entering a second list of one or more SIDs into the BFD request packet, the second list of one or more SIDs defining an SR-TE reverse path back from the destination node that eliminates involvement of a BFD reflector of the destination node. Also, the process includes entering a revised-BFD request into the BFD request packet, the revised-BFD request having a Your Discriminator field set to a discriminator value associated with the source node.

Establishing forward and reverse segment routing (SR) tunnels for bidirectional forwarding detection (BFD) continuity checks

Systems, methods, and computer-readable media are provided for re-establishing a Bidirectional Forwarding Detection (BFD) session. A method, according to one implementation, include a step of receiving, at a local end device, a first BFD control packet from a remote end device when a BFD session between the local end device and remote end device is down. For example, the first BFD control packet may include a remote discriminator number associated with the remote end device and a local discriminator number presumed to be associated with the local end device. The method further includes a step of replying to the remote end device with a second BFD control packet including an actual discriminator number of the local end device in response to determining that the local discriminator number included in the first BFD control packet is non-zero and differs from the actual discriminator number of the local end device.

Re-establishing a bidirectional forwarding detection (BFD) session when a discriminator mismatch is detected

Systems and methods for incorporating a new channel-type value in the header of a Generic Associated Channel (G-ACh) for Connectivity Fault Management (CFM) Layer-2 packets over Multi-Protocol Label Switching (MPLS) networks are provided. The channel-type value of the G-ACh header may be used for identification of the network-generated CFM Layer-2 packets. In one implementation, a system may include a processing device and a memory device, where the memory device may be configured to store instructions that, when executed, cause the processing device to obtain a Connectivity Fault Management (CFM) packet, encapsulate the CFM packet with Pseudo-Wire (PW) and Label-Switched Path (LSP) labels to create an expanded packet, and incorporate a specific channel-type value in a G-ACh header of the expanded packet to uniquely identify the CFM packet.

Incorporating a generic associated channel (G-ACh) header and channel-type for connectivity fault management (CFM) packets over multi-protocol label switching (MPLS)

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New Delhi, India

Sudipta Das