Abstract: A network device may receive a border gateway protocol (BGP) flow specification route associated with creation of an overlay network slice in a network, and may create a new routing instance based on the BGP flow specification route. The network device may associate interfaces defined by the BGP flow specification route with virtual private network (VPN) members, and may determine VPN parameters based on the BGP flow specification route. The network device may advertise the VPN parameters within the network to cause the network to generate the overlay network slice.

Abstract: A ring node N belonging to a resilient MPLS ring (RMR) provisions and/or configures clockwise (CW) and anti-clockwise (AC) paths on the RMR by: (a) configuring two ring node segment identifiers (Ring-SIDs) on the ring node, wherein a first of the two Ring-SIDs (CW-Ring-SID) is to reach N in a clockwise direction on the ring and a second of the two Ring-SIDs (AC-Ring-SID) is to reach N in an anti-clockwise direction on the ring, and wherein the CW-Ring-SID and AC-Ring-SID are unique within a source packet routing in networking (SPRING) domain including the ring; (b) generating a message including the ring node's CW-Ring-SID and AC-Ring-SID; and (c) advertising the message, via an interior gateway protocol, for receipt by other ring nodes belonging to the ring such that (1) a clockwise multipoint-to-point path (CWP) is defined such that every other one of the ring nodes belonging to the ring can be an ingress for the CWP and such that only the node is an egress for the CWP, and (2) an anti-clockwise multipoint-

Abstract: A disclosed method may include (1) receiving, at a network node within a network, a packet from another network node within the network, (2) identifying, within the packet, a slice label that indicates a network slice that has been logically partitioned on the network, (3) determining a QoS policy that corresponds to the network slice indicated by the slice label, (4) applying the QoS policy to the packet, and then upon applying the QoS policy to the packet, (5) forwarding the packet to an additional network node within the network. Various other apparatuses, systems, and methods are also disclosed.

Abstract: In general, techniques are described for signaling IP path tunnels for traffic engineering using constraints in an IP network. For example, network devices, e.g., routers, of an IP network may compute an IP path using constraint information and establish the IP path using, for example, Resource Reservation Protocol, to signal the IP path without using MPLS. As one example, the egress router generates a path reservation signaling message that includes an egress IP address that is assigned for use by the routers on the IP path to send traffic of the data flow by encapsulating the traffic with the egress IP address and forwarding toward the egress router. As each router in the IP path receives the path reservation signaling message, the router configures a forwarding state to forward traffic encapsulated with the egress IP address to a next hop along the IP path toward the egress router.

Abstract: A network device may receive an MPLS packet destined for a destination via a label-switched path (LSP), and may determine whether to apply a first special purpose label (SPL) option or a second SPL option for a label stack of the MPLS packet. The network device may apply, when the first SPL option is determined to be applied, one of a first type of the first SPL option for the label stack via a policy data indicator (PDI) and policy data (PD), or a second type of the first SPL option for the label stack via the PDI and the PD. The network device may forward the MPLS packet to a hop of the LSP based on the first type of the first SPL option or the second type of the first SPL option applied to the MPLS packet.

Abstract: In general, techniques are described for signaling IP path tunnels for traffic engineering using constraints in an IP network. For example, network devices, e.g., routers, of an IP network may compute an IP path using constraint information and establish the IP path using, for example, Resource Reservation Protocol, to signal the IP path without using MPLS. As one example, the egress router generates a path reservation signaling message that includes an egress IP address that is assigned for use by the routers on the IP path to send traffic of the data flow by encapsulating the traffic with the egress IP address and forwarding toward the egress router. As each router in the IP path receives the path reservation signaling message, the router configures a forwarding state to forward traffic encapsulated with the egress IP address to a next hop along the IP path toward the egress router.

Abstract: In general, techniques are described for signaling IP path tunnels for traffic engineering using constraints in an IP network. For example, network devices, e.g., routers, of an IP network may compute an IP path using constraint information and establish the IP path using, for example, Resource Reservation Protocol, to signal the IP path without using MPLS. As one example, the egress router generates a path reservation signaling message that includes an egress IP address that is assigned for use by the routers on the IP path to send traffic of the data flow by encapsulating the traffic with the egress IP address and forwarding toward the egress router. As each router in the IP path receives the path reservation signaling message, the router configures a forwarding state to forward traffic encapsulated with the egress IP address to a next hop along the IP path toward the egress router.

Abstract: A tactical solution to network congestion is provided by a data forwarding device having (1) a first interface with a first link to a downstream data forwarding device and (2) second interface with a second link to a downstream data forwarding device, and executing a method comprising: (a) configuring the second interface as part of a loop-free alternate (LFA) path to a destination device, wherein the first interface is part of a shortest/preferred path to the destination device; (b) monitoring congestion at the first interface to determine whether or not the congestion exceeds a first threshold; and (c) responsive to a determination that the congestion exceeds the first threshold, forwarding at least some data addressed to the destination device, over the LFA path via the second interface instead of over the shortest/preferred path via the first interface, thereby alleviating congestion at the first interface, and otherwise, responsive to a determination that the congestion does not exceed the first threshol

Abstract: Support is provided for flexible algorithms, used by the border gateway protocol (BGP) route selection process, in the context of segment routing (SR) Prefix segment identifiers (SIDS) advertised using BGP.

Abstract: In some implementations, a network device may identify a segment routing traffic engineering (SR-TE) algorithm supported by the network device. The network device may determine, based on identifying the SR-TE algorithm, an identification value associated with the network device. The network device may generate an advertisement packet that includes the identification value and information identifying the SR-TE algorithm. The network device may send the advertisement packet to another network device to cause the other network device to update a data structure to indicate that the network device supports the SR-TE algorithm and that the network device is associated with the identification value. The other network device may determine, using the SR-TE algorithm, a forwarding path for a data packet that indicates the network device as a hop in the forwarding path.

Abstract: In some implementations, a network device may identify a segment routing traffic engineering (SR-TE) algorithm supported by the network device. The network device may determine, based on identifying the SR-TE algorithm, an identification value associated with the network device. The network device may generate an advertisement packet that includes the identification value and information identifying the SR-TE algorithm. The network device may send the advertisement packet to another network device to cause the other network device to update a data structure to indicate that the network device supports the SR-TE algorithm and that the network device is associated with the identification value. The other network device may determine, using the SR-TE algorithm, a forwarding path for a data packet that indicates the network device as a hop in the forwarding path.

Abstract: In general, this disclosure describes a network device to determine a cause of packets being dropped within a network. An example method includes generating, by a traffic monitor operating on a network device, an exception packet that includes a unique exception code that identifies a cause for a component in the network device to discard a transit packet, and a nexthop index identifying a forwarding path being taken by the transit packet experiencing the exception. The method also includes forwarding the exception packet to a collector to be processed.

Abstract: The same prefix segment identifier (SID) may be configured and/or used for either (A) more than one prefix within an interior gateway protocol (IGP) domain, or (B) one prefix with more than one path computation algorithm within the IGP domain by: (a) receiving, by a node in the IGP domain, an IGP advertisement including both (1) a prefix SID and a segment routing global block (SRGB) slice identifier; (b) determining whether or not the SRGB slice identified by the SRGB slice identifier is provisioned on the node; and (c) responsive to a determination that the SRGB slice identified by the SRGB slice identifier is not provisioned on the node, not processing the prefix SID included in the received IGP advertisement, and otherwise responsive to a determination that the SRGB slice identified by the SRGB slice identifier is provisioned on the node, (1) processing the prefix SID and SRGB slice to generate a unique, per SRGB slice, MPLS label for the prefix, and (2) updating a label forwarding information base (LFIB)

Abstract: In general, this disclosure describes a network device to determine a cause of packets being dropped within a network. An example method includes generating, by a traffic monitor operating on a network device, an exception packet that includes a unique exception code that identifies a cause for a component in the network device to discard a transit packet, and a nexthop index identifying a forwarding path being taken by the transit packet experiencing the exception. The method also includes forwarding the exception packet to a collector to be processed.

Abstract: A disclosed method may include (1) receiving, at a network node within a network, a packet from another network node within the network, (2) identifying, within the packet, a slice label that indicates a network slice that has been logically partitioned on the network, (3) determining a QoS policy that corresponds to the network slice indicated by the slice label, (4) applying the QoS policy to the packet, and then upon applying the QoS policy to the packet, (5) forwarding the packet to an additional network node within the network. Various other apparatuses, systems, and methods are also disclosed.

Abstract: The same prefix segment identifier (SID) may be configured and/or used for either (A) more than one prefix within an interior gateway protocol (IGP) domain, or (B) one prefix with more than one path computation algorithm within the IGP domain by: (a) receiving, by a node in the IGP domain, an IGP advertisement including both (1) a prefix SID and a segment routing global block (SRGB) slice identifier; (b) determining whether or not the SRGB slice identified by the SRGB slice identifier is provisioned on the node; and (c) responsive to a determination that the SRGB slice identified by the SRGB slice identifier is not provisioned on the node, not processing the prefix SID included in the received IGP advertisement, and otherwise responsive to a determination that the SRGB slice identified by the SRGB slice identifier is provisioned on the node, (1) processing the prefix SID and SRGB slice to generate a unique, per SRGB slice, MPLS label for the prefix, and (2) updating a label forwarding information base (LFIB)

Abstract: An example network element includes one or more interfaces and a control unit, the control unit includes one or more processors configured to determine an egress network domain identifier (ID) and determine an abstracted interdomain network topology. The one or more processors are also configured to determine one or more interdomain paths from an abstracted ingress domain node to an abstracted egress domain node and determine whether an abstracted domain node is on the one or more interdomain paths. The one or more processors are configured to, based on the abstracted domain node being on the one or more interdomain paths, include one or more resources within a network domain in a filtered traffic engineering database (TED) and compute a path from an ingress node within the ingress network domain to an egress node within the egress network domain based on the filtered TED.

Abstract: The disclosed computer-implemented method may include (1) receiving, at a network node within a network, a packet from another network node within the network, (2) identifying, within the packet, a label stack that includes a plurality of labels that collectively represent at least a portion of a label-switched path within the network, (3) popping, from the label stack, a label that corresponds to a next hop of the network node, (4) determining, based at least in part on the label, that the next hop has experienced a failure that prevents the packet from reaching a destination via the next hop, (5) identifying a backup path that merges with the label-switched path at a next-to-next hop included in the label-switched path, and then (6) forwarding the packet to the next-to-next hop via the backup path. Various other methods, systems, and apparatuses are also disclosed.

Abstract: Techniques are described for class-based traffic engineering in an IP network. For example, routers of an IP network may establish one or more constrained traffic engineered paths using a link-state protocol (e.g., IGP) without using signaling protocols, such as RSVP or SPRING, or encapsulating packets over MPLS. For example, an egress router of the IP network may receive a capability message specifying the capability of routers to compute a constrained path to the egress router, wherein the capability message comprises path computation information including an identifier of a path computation algorithm to be used by the one or more of the plurality of network devices to reach the egress network device. The egress router may advertise a reachability message including a destination IP prefix and the identifier of the path computation algorithm to cause routers in the IP network to compute the constrained path to reach the egress router.

Abstract: A ring node N belonging to a resilient MPLS ring (RMR) provisions and/or configures clockwise (CW) and anti-clockwise (AC) paths on the RMR by: (a) configuring two ring node segment identifiers (Ring-SIDs) on the ring node, wherein a first of the two Ring-SIDs (CW-Ring-SID) is to reach N in a clockwise direction on the ring and a second of the two Ring-SIDs (AC-Ring-SID) is to reach N in an anti-clockwise direction on the ring, and wherein the CW-Ring-SID and AC-Ring-SID are unique within a source packet routing in networking (SPRING) domain including the ring; (b) generating a message including the ring node's CW-Ring-SID and AC-Ring-SID; and (c) advertising the message, via an interior gateway protocol, for receipt by other ring nodes belonging to the ring such that (1) a clockwise multipoint-to-point path (CWP) is defined such that every other one of the ring nodes belonging to the ring can be an ingress for the CWP and such that only the node is an egress for the CWP, and (2) an anti-clockwise multipoint-