Cisco Technology, Inc.

Ciena Corporation

Muthurajah Sivabalan

Sami Boutros

David Delano Ward

Clarence Filsfils

Jean-Philippe Vasseur

George Swallow

Stefano Benedetto Previdi

Tarek Saad

Zafar Ali

Rakesh Gandhi

Ashwath Narasimhan

Tao Wang

Carlos M Pignataro

Stewart Frederick Bryant

Cengiz Alaettinoglu

Himanshu Shah

Rex Emmanuel Fernando

Luca Martini

Carol Etta Iturralde

Santiago Alvarez

Lakshmi Rajasekaran

Jerome Henry

Nagendra Kumar Nainar

Robert Edgar Barton

Jan Medved

Ian Michael Charles Shand

Francois Clad

John Galen Scudder

John H W Bettink

Reshad Rahman

Pradosh Mohapatra

Yuri Tsier

Amal Karboubi

Lakshmi Sharma

Santiago Vazquez Freitas

Peng He

Bruce McDougall

Rodolphe Figaro

Show Chung Chin

Robert Keith Fielding

Peter Psenak

Syed Kamran Raza

Maik Guenter Seewald

Daniel C Frost

Robert Goguen

Robert H Thomas

Nobushige Akiya

Arun Prakash

Anca Zamfir

Simon James Trevor Spraggs

Michael Alan Kowal

Pranav Mehta

Bertrand Duvivier

Arjun Sreekantiah

Sowmya Chandran

Simon Spraggs

Nagi Reddy Jonnala

Ramesh Uppili

Frédéric Perras

Ram Parameswaran

Jahanzeb Baqai

Jean Philippe Vasseur

A node configured to operate in a network that operates one or more of Internet Protocol version 6 (IPv6) and Segment Routing over IPv6 (SRv6), the node comprising circuitry configured to receive a packet from another node in the network, wherein the node supports both a reduced mode and a non-reduced mode, and determine whether there is an identifier in the packet that indicates whether the packet is based on the reduced mode or the non-reduced mode. The identifier can be utilized to determine whether a destination address in the packet is either an IPv6 destination address or an SRv6 micro-Segment Identifier (uSID).

Distinguishing SRv6 micro-SID destination address from IPv6 destination address

Systems and methods associated with a node in a Segment Routing network include, responsive to what services are support at a node in a Segment Routing network, creating a bitmap to represent the plurality of services supported at the node; and transmitting an advertisement with the bitmap such that the advertisement is a single advertisement of multiple services. This approach can reduce the advertisement of rout updates by orders of magnitude.

Bitmap signaling of services using segment routing

Systems and methods include, in a node in a Segment Routing network, learning an adjacency Segment Identifier (SID) of a directly connected neighbor; and programming forwarding entries including a primary path and backup path associated with the adjacency SID. The programming is only performed for adjacency SIDs of directly connected neighbors, for use as a Point of Local Repair (PLR). This addresses holes in Topology Independent Loop Free Alternative (TI-LFA) node protection scheme for Segment Routing Traffic Engineering (SR-TE) paths.

Control plane based enhanced TI-LFA node protection scheme for SR-TE paths

A node in a segment routing version 6 (SRv6) network includes circuitry configured to transmit and receive packets in the SRv6 network with a segment routing header (SRH) that supports one or more of a Reduced mode and a Non-reduced mode, transmit via transmitted routing updates to one or more nodes in the SRv6 network which of the one or more of the Reduced mode and the Non-reduced mode are supported by the node, and receive via received routing updates from the one or more nodes their corresponding support for the one or more of the Reduced mode and the Non-reduced mode.

Distribution of SRv6 modes of operation via routing protocols

Systems and methods for Segment Routing Traffic Engineering (SR-TE) with awareness of local protection include the advertisement of local protection information in effect at each SR capable node via Interior Gateway Protocol (IGP), Border Gateway Protocol Link-State advertisement (BGP-LS), telemetry, etc. This information can include identity (IP address) of protected elements (link/node), type of protection (node, link, SRLG), a SID list for the backup path, whether protection is active, etc. This information can also be advertised via Path Computation Element Protocol (PCEP) as well. The information can also include a Binding SID (BSID) in the advertisement for local backup paths. Further, the present disclosure can enable a new SR OAM message (probe) to instruct a node to activate/deactivate a specific backup path in the forwarding plane for testing purposes.

Segment routing traffic engineering (SR-TE) with awareness of local protection

A node in a Segment Routing Internet Protocol version 6 (SRv6) network includes circuitry configured to, for a packet destined to a Service Function Chain (SFC), encode one or more micro-Segment Identifiers (uSIDs) for the SFC, wherein at least one uSID of the one or more uSIDs includes an Endpoint Behavior field, responsive to the at least one uSID needing one or more Arguments, include the one or more Arguments after the Endpoint Behavior field, and transmit the packet towards the SFC. The present disclosure presents various techniques to utilize uSIDs for SFC.

Service Function Chaining using uSID in SRv6

Systems and methods implemented in a network element in a Segment Routing network include, for a service having two or more candidate paths and responsive to a failure on a current candidate path of the two or more candidate paths, setting an eligibility flag for the current candidate path; and selecting another candidate path of the two or more candidate paths, for the service, based on their eligibility flag.

Emulating MPLS-TP behavior with non-revertive candidate paths in Segment Routing

Systems and methods for micro-loop avoidance include detecting a remote link failure in a network and identifying an associated Point of Local Repair (PLR); determining destinations in the network that are impacted due to the remote link failure; and installing of a temporary tunnel to the PLR. The steps can further include sending traffic destined for nodes impacted by the remote link failure via the temporary tunnel to the PLR. The temporary tunnel can be implemented by a node Segment Identifier (SID) for the PLR.

Micro-loop avoidance in networks

A node configured to operate in a network that operates one or more of Internet Protocol version 6 (IPv6) and Segment Routing over IPv6 (SRv6), the node includes circuitry configured to determine a packet is to be sent to a second node in the network, with both the node and the second node utilizing Reduced Mode micro-Segment Identifiers (uSIDs), and include an identifier in an IPv6 header of the packet denoting a destination address of the packet includes uSIDs. The circuitry can be further configured to include the identifier responsive to a determination the second node supports the identifier.

Systems and methods for incrementally eliminating Border Gateway Protocol&#x2014;Labeled Unicast (BGP-LU) in a multi-region network include receiving BGP-LU updates from one or more Area Border Router (ABR) nodes in a multi-region network with the ABR nodes between two areas including a first area utilizing Segment Routing without utilizing BGP-LU and a second area utilizing BGP-LU; and, responsive to a request from a first node in the first area to reach a second node in the second area, providing a Segment Identifier (SID) list to the first node where the SID list is determined based on the Segment Routing in the first area and the BGP-LU updates from the second area.

Incrementally eliminating BGP-LU using SR policies and PCE

Systems and methods in a node in an MPLS network include determining a plurality of services supported at the node; determining a bitmask to represent the plurality of services supported at the node, wherein the bitmask includes a starting service and each subsequent bit representing another service of the plurality of services and with each bit in the bitmask set based on the plurality of services supported at the node; and transmitting an advertisement to other nodes in the network with the bitmask based on the plurality of services supported at the node. The steps can further include transmitting a packet associated with a service of the plurality of services with an MPLS label stack including one or more transport labels for a destination of the packet, a service label identifying the service, and a source label identifying a source Internet Protocol (IP) address of the packet.

Optimized L2/L3 services over classical MPLS transport

A method implemented in a network element includes, for a service, receiving a Segment Identifier (SID) list and an explicit list for an intended path in a Segment Routing network; expanding the SID list and comparing the expanded SID list to the explicit list; and setting the intended path as either valid or invalid based on the comparing. The intended path can be a primary path, and the steps can further include receiving a SID list and an explicit list for a backup path in the Segment Routing network. The steps can further include switching to the backup path responsive to a failure on the primary path, and switching back to the primary path responsive to it being valid.

Handling diversity constraints with Segment Routing and centralized PCE

Systems and methods include determining a Multi-Point to Point (MP2P) tree from a plurality of source nodes to a destination node in a Segment Routing network, wherein the plurality of source nodes are sending traffic with guaranteed bandwidth requirements to the destination node, and wherein the MP2P tree is determined based on the guaranteed bandwidth; assigning a globally unique Segment Identifier (SID) for the MP2P tree; and causing programming of forwarding entries in the plurality of source nodes, any intermediate nodes, and the destination node, based on the MP2P tree. The steps can further include receiving measurements from nodes on the MP2P tree of bandwidth utilized against the globally unique SID; and updating the MP2P tree if required based on the measurements. Each of the plurality of source nodes utilize the globally unique SID to send traffic with guaranteed bandwidth requirements to the destination node.

Centralized approach to SR-TE paths with bandwidth guarantee using a single SID

Systems and methods include obtaining a plurality of services supported at the node; determining a bitmask to represent the plurality of services supported at the node, wherein the bitmask includes a starting service and each subsequent bit representing another service of the plurality of services and with each bit in the bitmask set based on the plurality of services supported at the node; and transmitting an advertisement to nodes in the Segment Routing network with a starting Service SID value and the bitmask based on the plurality of services supported at the node. The plurality of services can include any of a Virtual Private Wire Service (VPWS) and a Flexible Cross Connect (FXC) service.

VPWS signaling using segment routing

Systems and methods for creating loopback packets for transmission through a section of a network for the purpose of testing the operability of links and nodes in this section of the network are provided. A method, according to one implementation, includes a step of obtaining information, by a Network Element (NE), about the topology of the network related to at least the nodes in direct communication with a peer node. The method also includes a step of generating one or more loopback packets, where each loopback packet includes at least a header having a path list including one or more nodes of the plurality of nodes in the network. Each path list defines an order of nodes through which the respective loopback packet is to be transmitted.

Creating a packet with a loopback label stack to detect network link/node failures

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Kanata, Canada

Muthurajah Sivabalan