Juniper Networks, Inc.

Yimin Shen

Raveendra Torvi

Yakov Rekhter

John E Drake

Ravi I Singh

Minjie Dai

Zhaohui Zhang

Ronald P Bonica

Nitin Bahadur

Harish Sitaraman

Ina Minei

Markus Jork

Natrajan Venkataraman

Adrian John Farrel

Alexander Arseniev

Rahul Aggarwal

Shraddha Hegde

Wen Lin

Nischal Sheth

Ross W Callon

Chandrasekar Ramachandran

Junan Chen

Vishnu Pavan Kumar Beeram

Disha M Chopra

Krzysztof Grzegorz Szarkowicz

Wai Tong Louis Chan

Dhiman Barman

Ahmed R Darwish

Christopher J Tripp

Brindhavathy Radhakrishnan

A network node may receive a packet that originated from a root network node and may process the packet to determine segment identifier (SID) information associated with a point-to-multipoint transport chain. The network node may determine, based on the SID information, that the network node is a transit leaf node in the point-to-multipoint transport chain. The network node may generate, based on determining that the network node is a transit leaf node in the point-to-multipoint transport chain, a copy of the packet and may process the copy of the packet to perform one or more actions. The network node may update, based on determining that the network node is a transit leaf node in the point-to-multipoint transport chain, the SID information and may send, after updating the SID information, the packet, with the updated SID information, to another network node.

Point-to-multipoint transport chain

A network node may receive an indication of a range of network address prefixes and a corresponding range of sequential identifiers. The network node may generate a policy for mapping respective network address prefixes, having ordered positions within the range of network address prefixes, to respective identifiers having corresponding ordered positions within the corresponding range of sequential identifiers. The network node may discover a device associated with a network address having a network address prefix at an ordered position within the range of network address prefixes. The network node may map, based on the policy, the network address prefix to an identifier having an ordered position within the corresponding range of sequential identifiers, wherein the ordered position within the corresponding range of sequential identifiers corresponds to the ordered position within the range of network address prefixes. The network node may advertise the mapping to one or more neighbor nodes.

Prefix range to identifier range mapping

Techniques are disclosed for service-based tunnel selection for forwarding network traffic. In one example, a network device obtains, based on service parameters associated with a network service, a service-specific tunnel selection scheme. The tunnel selection scheme identifies a primary mapping mode for mapping the network service to a primary transport tunnel and fallback mapping modes for mapping the network service to fallback transport tunnels. The primary mapping mode is categorized according to a first type comprising tunnel colorization, while the fallback mapping modes are categorized according to types other than tunnel colorization. In response to determining that the network service cannot be mapped to the primary transport tunnel according to the primary mapping mode, the network device, maps, based on the fallback mapping modes, the network service to the fallback transport tunnels. The network device forwards network traffic associated with the network service via the fallback transport tunnels.

Service-based tunnel selection scheme for mapping services to tunnels

Techniques are described for inter-domain segment routing using transport endpoint segments. A transport endpoint segment provisioned on a router within a domain represents any intra-domain tunnel originated at the router and having reachability to an indicated endpoint within the same domain. The provisioning router advertises a transport endpoint segment identifier (TESID) for the transport endpoint segment to other routers or a controller for use in segment routing. The TESID for the transport endpoint segment remains constant regardless of which intra-domain tunnel is bound to the transport endpoint segment. The provisioning router dynamically binds the transport endpoint segment to at least one intra-domain tunnel, and any changes to the bound intra-domain tunnel are updated locally at the provisioning router. In this way, an inter-domain segment routing tunnel may be constructed as a list TESIDs that are not affected by intra-domain tunnel changes.

Transport endpoint segments for inter-domain segment routing

Techniques are described for reusing downstream-assigned labels when establishing a new instance of a label switched path (LSP) prior to tearing down an existing instance of the LSP using make-before-break (MBB) procedures for RSVP. The techniques enable a routing engine of any non-ingress router along a path of the new LSP instance to reuse a previously allocated label for the existing LSP instance as the downstream assigned label for the new LSP instance when the paths of the existing LSP instance and the new LSP instance overlap. In this way, the non-ingress router does not need to update a label route in its forwarding plane for the reused label. When the new LSP instance completely overlaps the existing LSP instance, an ingress router of the LSP may avoid updating an ingress route in its forwarding plane for applications that use the LSP.

RSVP make-before-break label reuse

Techniques are described for establishing a second label switched path (LSP) instance of an LSP having a first LSP instance. In one example, for each downstream router designated for the second LSP instance of the LSP, the router determines whether the router is part of the first instance of the LSP and, if so, whether the first and second LSP instances for that downstream router share a common link to a nexthop router. If the first and second LSP instances share a common link to a nexthop router, the downstream router transmits a first message to the nexthop router, wherein the first message includes a suggested label. The downstream router receives, from the nexthop router, a second message, wherein the second message includes the suggested label. In another example, a label reuse indicator flag in a message from the ingress router causes routers on the second LSP instance to reuse the label of the first LSP instance when the same link is used to the upstream router for both LSP instances.

In general, techniques are described for a path computation delay timer for multi-protocol label switched networks. As an example, an ingress network device configured to act as an ingress for a label switched path (LSP) may perform the techniques. The ingress network device comprises an interface and a processor. The interface may receive a message indicating an error along the LSP. The processor may delay an operation performed to configure a replacement LSP to be used in place of the LSP in order to provide time during which a cause of the error along the LSP is able to be determined. When the cause of the error is determined to be a failure of a network device supporting operation of the LSP, the processor may further perform the operation to configure the replacement LSP with the ingress network device such that the replacement LSP avoids the failed network device.

Path computation delay timer in multi-protocol label switched networks

In one example, a stitching point routing device, which stitches a previous segment of an end-to-end label-switched path (LSP) to a next segment of the end-to-end LSP, includes network interfaces configured to receive packets via the previous segment and send packets via the next segment, and one or more processors configured to determine whether the next segment supports entropy labels, determine whether a packet received from the previous segment is encapsulated by a label stack including an entropy label, when the next segment does not support entropy labels and when the packet is encapsulated by the label stack including the entropy label, remove the entropy label from the label stack, when the next segment supports entropy labels and when the packet is not encapsulated by the label stack including the entropy label, add an entropy label to the label stack, and forward the packet along the next segment.

Handling entropy labels when stitching label-switched paths

In one example, a method includes establishing a plurality of label switched paths (LSPs) having a common transit network device other than an ingress network device or an egress network device of any of the plurality of LSPs, and, by the transit network device along the plurality of LSPs, detecting a congestion condition on a link along the plurality of LSPs and coupled to the transit network device. The method also includes, responsive to detecting the congestion condition, and by the transit network device, selecting a subset of the plurality of LSPs to evict from the link, wherein the subset comprises less than all of the plurality of LSPs, and updating a forwarding plane of the transit network device to reroute network traffic received for the selected subset of the plurality of the LSPs for forwarding to a next hop on a bypass LSP that avoids the link.

Selective label switched path re-routing

A label switched path (LSP) is established within a network using an MPLS fast reroute bypass tunnel when a resource along a primary path of the LSP has failed but is protected by the MPLS fast reroute bypass tunnel. While establishing the LSP, a network device identifies a failed resource along a primary path of the LSP. In response to identifying the failed resource, the network device determines whether a bypass tunnel exists from the network device to a node along the primary path, wherein the bypass tunnel avoids the failed resource. Upon determining that the bypass tunnel exists, the network device tunnels a message for establishing the LSP to the node over the bypass tunnel.

Label switched path setup using fast reroute bypass tunnel

An aggregation node establishes a first session using a traffic-engineering label distribution protocol. The first session has a next hop adjacent to the aggregation node and positioned within a same network as the aggregation node. The aggregation node also establishes a second session using a traffic-engineering label distribution protocol, wherein the second session has a remote next hop positioned at a border between the network and a second network. The aggregation node sends a message destined for the remote next hop over the second session for establishing an end-to-end traffic engineered label switched path for a FEC specified in a label request message received from an access node, wherein the message includes the same the data indicating constraint information that was received by the aggregation node in the label request message.

End-to-end traffic engineering label switched paths in seamless MPLS

Techniques are described for establishing a point-to-multipoint (P2MP) label switched path (LSP) using a branch node-initiated signaling model in which branch node to leaf (B2L) sub-LSPs are signaled and utilized to form a P2MP LSP. The techniques described herein provides a scalable solution in which the number of sub-LSPs for which the source node or any given branch node need maintain state is equal to the number of physical data flows output from that node to downstream nodes, i.e., the number of output interfaces used for the P2MP LSP by that node to output data flows to downstream nodes. As such, unlike the conventional source node-initiated model in which each node maintains state for sub-LSPs that service each of the leaf nodes downstream from the device, the size and scalability of a P2MP LSP is no longer bound to the number of leaves that are downstream from that node.

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Shrewsbury, MA, United States of America

Yimin Shen